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So You Want To Be a Tech “Insider”By Bryan Lambert – Sunday, December 21, 2008 |
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Often in my travels people ask me: “Where did you learn so much about computers and electronics?” “Why,” I say, “the answer is easy – I got a
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Environment variables are specially named aliases or placeholders for certain basic system properties that are present for convenience in programming and in system administration. Although they are mostly of interest to technical people, some can be useful to the average PC user and these are discussed here.
Environment variables have long been used in computer operating systems and are present in Unix, DOS, and Windows The word "environment" used in the context here refers to various features of the computer system and certain basic system data. Here is one of Microsoft's definitions:
Values for some of these variables are established at login and these are sometimes called predefined variables. They include such parameters as the path and the name of the current user. A table of some of the more useful variables is given below. I have omitted some of the more technical ones. A more complete list is at this Microsoft reference. The variables are enclosed by percent signs when used in scripts or the command line, as is shown in the table. Although the variables are shown in upper case, they are not case-sensitive. More details are given about some of them in subsequent sections. (To conform to much of the literature on environment variables, I will be using the term "directories" instead of "folders" in the discussion.)
The so-called predefined variables are generally unchanged during a login session but there are also some dynamic variables whose value may change. Some of these are listed in the next table.
Environment variables are very convenient in scripts where certain standard directories and parameters need to be referenced but where the actual locations or names can vary from computer to computer.(Note that the presence of spaces in some names may necessitate the use of enclosing quotation marks around environment variables in scripts.) By having a placeholder, no prior knowledge is required of such details as the exact location of Windows or who is logged in. Some possibilities are explored in the following sections. The PATH Environment VariableThe path to a file is basically its address on the computer. It tells programs how to find a file. It is the drive plus any directories and sub-directories where the file is located. The %PATH% environment variable specifies the command search path. Typically, this is a group of directories where executable files that are repeatedly used are to be found. Examples of the default values are listed in the first table above; in this case, they are the Windows directory and two of its important system sub-directories. To see what is in the PATH variable on a computer, open a command window and enter "echo %PATH%". The PATH variable is not immutable and programs like Norton SystemWorks will stick themselves into PATH when they are installed. The PC user can also modify the contents using methods discussed further on. Adding directories to PATH can be very useful if you use scripts or the command line for system maintenance. For example, it can be convenient to put the directory where you keep backups into the PATH variable. It can also be useful to modify PATH if you put programs in a directory different from the usual one. In the command line and in batch files, PATH can be modified by the command path = dir1;dir2;dir3 This command will create a PATH environment variable consisting of the three directories dir1, dir2, and dir3. Note that the directory names are separated by a semicolon in the command statement. (An alternate form omits the "equals" sign.) This command will replace any previous directories that were in the PATH variable. To add a directory "newdir" to the current path use the statement path = %PATH%;newdir It is essential to remember that any changes that are made in a command window only endure until the window is closed. For permanent changes, use the method discussed in another section. It is also possible to use the command-line executable setx.exe that is contained in the Windows XP Service Pack 2 Support Tools. Any file that is in a directory listed in the PATH variable can be found or opened by direct reference to the name of the file without having to specify the drive and directories where it is located. This is very handy in scripting and in other ways. For instance, the name of an executable file that is in a directory listed in the PATH variable can be entered into Start-Run to open certain applications (more on this subject here). An example is the executable file for the classic version of the game Solitaire that is generally in the system folder C:\Windows\System32\. The file is sol.exe and its full address with complete path is C:\Windows\System32\sol.exe. Normally this entire string would have to be used in order to reference the Solitaire game. Because its directory is listed in the PATH variable, however, it is sufficient to reference just the file name sol.exe. In fact, because of another environment variable PATHEXT discussed next, simply entering sol into Start-Run is sufficient to open the solitaire game. The PATHEXT VariableAs is explained on other cialis generic vs brand pages, file extensions tell Windows what it is supposed to do with a file. Certain file extensions indicate that the file is executable; that is, the file opens a program or does something. The %PATHEXT% environment variable contains executable file extensions that do not have to be specified for any file in a directory given in the %PATH% variable. The extension .EXE is the most common. Thus the filename sol.exe need only be entered as sol in a command line. If files have the same name but different extensions, the operating system searches in the following order of precedence: .EXE, .COM, .BAT, and .CMD. Adding or Editing Environment VariablesExisting variables can be edited or deleted and new ones can be added in several ways. For temporary changes, the command " Set" can be used in scripts or in a command window. An example is shown below: set temp=C:\tempHere, the %TEMP% directory has been changed from the default value. Note that the there must be no spaces on either side of the "equals" sign. Changes made with "Set" disappear when the command window is closed, thus rendering this method fairly uninteresting for the average PC user. A more useful application of "Set" is to list the environment variables. Open a command window and enter "set" to see what the variables are on your system. Those who wish can consult this Microsoft article for more details about "Set". A more permanent way to manage environment variables is provided in the System Properties dialog box. Open Control Panel-Performance and Maintenance-System (or right-click on My Computer and choose "Properties"). In the box that opens, click the "Advanced" tab to obtain the dialog box shown below. Next, click the button "Environment Variables".
The figure below shows the "Environment Variables" dialog box that opens next. It lists two kinds of variable- those that apply only to the current user and those that apply to the whole system. You can simply scroll down the lists to see what is on your system or you can edit the lists. Note that I have created a user variable %BACKUP% that gives the path to my one of my backup directories. That makes it easier for me to write a backup script since all I have to do is enter %BACKUP% whenever I want to refer to this directory. To create a new variable, use the "New" button. There are also buttons for editing and for deleting variables.
The box for adding a new user variable is shown below. Generally, this is likely to be a directory that you use frequently but can be any string of less than 8192 bytes. The maximum total size for all environment variables, including variable names and the "equals" sign, is 32767 characters.
The next figure shows a box for editing a variable; in this case it is the PATH variable. Be sure to remember to separate directory names with a semicolon. If you use programs in a particular directory a great deal, you may wish to add it to the path. The figure shows that the directory "G:\Program Files\Support Tools\" has been added.
Using the add-on tool Setx.exeIt is not part of the standard Windows XP setup but a command-line tool called setx.exe is included in the Windows XP Service Pack 2 Support Tools. This tool extends the set command so that permanent changes in the environment variables can be made. For example, to add a folder C:\New Folder to the path, the command would be setx path "%PATH%;C:\New Folder" Scripts for Listing Environment VariablesThe "Set" command can be used in a command prompt together with a redirection to a text file to make a list of the current environment variables. The command might be set > C:\env_list.txt The file name "C:\env_list.txt" can be replaced by any of your choice. Microsoft also has a VBScript that lists environment variables on this page. Registry Keys for Environment VariablesFor those who are experienced with editing the Registry, there is another way to make changes in environment variables. User environment variables are stored in the Registry in the key: Note that any environment variable that is in the form that needs to be expanded (for example, %PATH%) must be stored in the registry as a REG_EXPAND_SZ registry value. Editing the Registry is primarily for scripts used by systems administrators and is not recommended for the average PC user. Setting Environment Variables in Autoexec.batThe file autoexec.bat is a relic from DOS and older versions of Windows but may still be present in some systems. For the most part, Windows XP will ignore any autoexec.bat file but entries defining environment variables will be picked up. Although environment variables can be set in this way, there are probably better ways. Environment variables in VistaThe same general considerations hold but there are differences in the details of environment variables for Vista. These are discussed at vistaonwindows.com. |
The UIF file extension stands for Universal Image Format. An UIF file contains a compressed disk image – basically it is an exact copy of a CD or a DVD. Just like the more common ISO filetype, the UIF format is typically used to create CD/DVD backups. The UIF file format also offers several advanced features that ISO doesn’t have, like the data compression I mentioned previously. The UIF image can also be encrypted and password protected, and it can be used to backup multi-session disks in a single file.
UIF is a proprietary file format used by the MagicISO software. At the moment it is the only tool that can open or extract UIF files. The full version of MagicISO costs money, but you can download a free trial that will be able top open UIF files just fine. You can get the trial from MagicISO.com. Once you’ve installed it, you can just double-click the UIF file to open it.
Sometimes it’s very useful to convert the UIF image to the more popular ISO file type which is supported by most, if not all, CD/DVD tools. Luckily this can be done with the free trial of MagicISO (see above), but only for files that are under 300MB.
Update : Use my UIF to ISO converter GUI (freeware) to convert UIF files of any size.
Here are step-by-step instructions for converting UIF to ISO :
Note : the above instructions apply to MagicISO 5.4, which is the newest version at the time of writing.
When you need to burn UIF files to a CD/DVD you have several options :
It is also possible to mount .uif files to a virtual CD/DVD drive. You will then be able to access the virtual disc as if it was a real CD/DVD. To do this you will need to install cialis generic price target=”_blank”>MagicDisc (freeware). Once you’ve done that, you can mount the UIF file by following these steps :
You could also convert the UIF files to ISO and use a different CD/DVD emulator (e.g. DaemonTools) to mount them.
So, this is everything you need to know to get started using UIF files
For the end user, increased productivity can be dependent on the familiarity of their working environment, which is encompassed in the Windows XP user profile.
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A user profile on a Microsoft Windows XP system contains all the files and settings needed to configure your work environment. If the user profile becomes damaged, Windows XP will display one of two error messages when you log on to the system:
Windows cannot load your profile because it may be corrupted. You may be logged in using a temporary User Profile.
OR:
The system has recovered from a serious error.
The operating system will then automatically create a new user profile and log you in to this new profile. When this occurs, you’ll immediately discover that all your personalized settings — such as color scheme, wallpaper, and icons — are gone. Even more disturbing is that the My Documents folder doesn’t show any of your documents. You’ll also discover that Outlook Express and Internet Explorer will be void of any of your personal settings and data.
When this happens, it’s very easy to quickly go into panic mode and think that you’ve lost everything. However, in most cases, all you’ve actually lost is the user profile and most, if not all, of your data is safe and sound.
This blog post is also available in PDF format as a TechRepublic download.
Keep in mind that in order to perform the recovery operations discussed in this article, you must be working from an account with Computer Administrator privileges. If the temporary account that Windows XP creates for you when your original becomes damaged has Computer Administrator privileges, you can use it as a staging area for the recovery operation. If it’s not, you’ll need to log off, then log on to the default Administrator account or to another account that has Computer Administrator privileges. I’ll refer to this as the “working account” throughout this article.
The first thing that you’ll want to do is make sure that the data in your original account is safe and then back it up. To begin the backup operation, launch Windows Explorer and navigate to the C:\Documents and Settings folder. Then, locate and cialis cheapest open your original account folder. At this point, you should see all the files and folders in your original user profile, as shown in Figure A.
You’ll then want to copy your crucial data files to another location. For example, you’ll definitely want to copy the contents of your My Documents folder, which will appear as UserName’sDocuments. (On my example system, it’s called Greg Shultz’s Documents.) You may also want to copy the contents of the Favorites folder. If you’re using Outlook Express, you can find the files that make up your e-mail messages stored in the Local Settings\Application Data\Identities\{#####}\Microsoft\Outlook Express folder. You’ll find your Address Book file in the Application Data\Microsoft\Address Book folder. If you’re using Outlook 2000/XP, you’ll find the PST file in the Local Settings\Application Data\Microsoft\Outlook folder.
Once you’ve backed up your crucial data files, you can proceed with the recovery operation knowing that your data is indeed safe and sound.
The first thing to try when attempting to recover a damaged user profile is a System Restore operation. As you know, the System Restore utility is designed to allow you to return your computer to the state it was at an earlier time period. In this case, the goal is to return your system to the state it was in before the user profile was damaged.
Before you attempt this operation, there are two things you need to be aware of. First, if there are multiple user accounts on the system, performing a System Restore operation will return all user profiles to the state they were in at that earlier time. Second, depending on the severity of the damage to the user profile, performing a System Restore operation may not be able to rectify the problem.
You’ll find the System Restore utility on the All Programs | Accessories | System Tools menu. Once you launch System Restore, you’ll see the Welcome To System Restore page and can simply click Next. On the Select A Restore Point page, select the last restore point created before the damage to the user profile became apparent, then click Next. When you’re prompted to confirm the operation, click Next, and the restore operation will begin.
Once System Restore finishes, it will restart the system. When it does, you can attempt to log on using your original user account. If System Restore was able to successfully recover the user profile, everything should be the way it was.
If you’re still unable to log on to your original account, it’s time to escalate your user profile recovery operation to the next level. However, you may first want to undo the System Restore operation.
To undo the System Restore operation, log on to the working account and launch System Restore. When you see the Welcome To System Restore page, you’ll discover a new option titled Undo My Last Restoration. Just select that option, click Next, and follow the onscreen instructions.
In this user profile recovery technique, you’ll attempt to revive the user profile by creating a new account and, subsequently, a new user profile. You’ll then copy your old user profile in its entirety to the new account. While this may sound like an operation that will simply replicate the problem over to the new account, it does indeed revive the user profile on occasion. Again, keep in mind that the success of this attempt depends on the severity of the damage to the user profile. However, since it’s a relatively painless operation, it’s worth a shot.
To begin, access the Control Panel and launch the User Accounts tool. Next, select the Create A New Account link. Then, give the account a name and click Next. When prompted to pick an account type, make sure the Computer Administrator option button is selected, and then click the Create Account button.
Once you create the new account, close the User Accounts tool. Then, click Start | Log Off. When you see the Log Off Windows dialog box, click the Log Off button. When either the Welcome Screen or the Log On To Windows dialog box opens, select or type the name you used for the new account. As soon as you do, Windows XP will create a user profile for the new account.
When the user profile creation procedure is complete and the system starts up, immediately click Log Off. Then, log back on to the working account.
Now, open the Start menu, right-click My Computer, and select Properties. When you see the System Properties dialog box, select the Advanced tab. Then, locate and click the Settings button in the User Profiles section. You’ll now see a User Profiles dialog box that looks like the one shown in Figure B.
In this example, I’ll be copying the user profile from the Greg Shultz account to the Greg Shultz2 account. I’ll begin by selecting the Greg Shultz user profile and clicking the Copy To button. When the Copy To dialog box appears, click the Browse button and then use the resulting Browse For Folder dialog box to locate the Documents and Settings folder and select the new account.
At this point, the Copy To dialog box will look like the one shown in Figure C. To continue, just click OK. You’ll then see a confirmation dialog box that informs you that the original files will be deleted and prompts you to confirm the copy operation. Just click Yes.
Once the copy operation finishes, close the User Profiles dialog box and the System Properties dialog box, then log off. At this point, you can attempt to log on to the new account. If this technique was able to successfully recover the user profile, everything should be the way it was.
If you’re still unable to log on to your account, it’s time to move to the next level. However, you’ll first need to completely remove the new user account and user profile. To do so, log on to the working account, access the User Profiles dialog box again, select the profile, and click the Delete button. Then, access the User Accounts tool and delete the new account and its files.
In this user profile recovery technique, you’ll move to a new user profile by creating a new account and, subsequently, a new user profile. You’ll then copy your data files and other portions of the user profile from your original to the new one. Keep in mind that when you move to a new user profile in this manner, you will lose all your personalized settings, such as color scheme, wallpaper, and icons.
You’ll follow the instructions I presented earlier for creating a new account and a new user profile. In short, you’ll access the User Accounts tool to create a new account. Then, log on to the new account to create a default new user profile. Finally, log off and then log back on to the working account.
To begin this operation, launch Windows Explorer and navigate to the C:\Documents and Settings folder. Then, locate and open your original account folder. At this point, you should see all the files and folders in your original user profile, as shown earlier in Figure A.
Copy the contents of the folders containing the data that you want to move to your new user profile. In the case of my example system, I’d begin by copying the contents of the C:\Documents and Settings\Greg Shultz\Greg Shultz’s Documents folder to the C:\Documents and Settings\Greg Shultz2\Greg Shultz2’s folder.
In addition, you’ll want to copy the contents of the Favorites, Outlook Express, and Address Book folders if you’re using that e-mail program, or the Outlook folder. You may also want to copy the contents of Cookies, Templates, and any other folders that contain critical data files.
Be careful not to copy any files that are specifically related to the operating system, as any one of those files could be the culprit in the case of the corrupted user profile. For example, you definitely won’t want to copy Ntuser.dat, Ntuser.pol, or Ntuser.ini from your old user profile to your new one.
When you’re finished copying files, log out of the working profile, and then log on to your new user profile. When you do, you should be able to access all your data files and most of your applications, just as you did with your old profile. However, keep in mind that you may have to reinstall or at least reconfigure some of your applications. And, of course, you’ll need to recreate all your personalized settings.
Once you’ve totally moved into your new user profile, you’ll want to permanently delete your old, corrupted user profile. While you may be tempted to do so from within Windows Explorer, you shouldn’t because it won’t completely remove all the settings associated with your old user profile.
To do it the right way, access the User Profiles tool from the Advanced tab of the System Properties dialog box. Once you do, select the old user profile from the list and click the Delete button.
So you won’t ever have to go through all these troubleshooting steps should the user profile ever get corrupted again, you can trick Windows XP into administering the local user profile as if it were a roaming user profile. When you do so, Windows XP will back up your user profile each time you log off.
To use this trick, you have to log off your new account and log on to the working account. Then, access the User Profiles tool from the Advanced tab of the System Properties dialog box, select your user profile, click the Copy To button, and type the name of a folder on another drive in the Copy Profile To text box.
Once you complete that part of the operation, launch the Computer Management console, which you can do by pressing [Windows]-R and typing compmgmt.msc in the Open text box. Then, drill down to System Tools\Local Users and Groups\Users folder. Next, double-click on your account name and select the Profile tab. Then, type the path to the backup in the Profile Path text box, as shown in Figure D.
Q:
I want to go through and remove some of the programs I know I have on my computer, but when I go to my Add/Remove Programs list, I can't find them. How can I get rid of them?
A:
That isn't uncommon. Some programs just like to be a little stubborn. Most Windows components can be uninstalled by going to the Add/Remove Windows Components section in the Control Panel. But, what about the ones you can't find? You know they're on your computer somewhere, but how can you get rid of them if you can't find them? Well, it's actually not too hard to bring these out of their hiding. Let's learn how!
Bring up the Windows Explorer (one way to do this is to right click on the Start button and select Explore).
Find your way to C:\Windows\Inf. (Double click on the My Computer icon on your desktop, double click on the C: drive and then go from there).
Make a copy of the "Sysoc.inf" file. (Click the file and hit Ctrl + C then Ctrl + V).
Next, right click "Sysoc.inf" and choose Open with, then Notepad.
Type Ctrl + H to bring up the Replace box.
Replace cialis buy cialis online ,hide, (comma hide comma) with ,, (comma comma).
Then hit the Replace All button.
Save the file.
Now, when you go to Start, Control Panel, Add/Remove Programs, Add/Remove Windows Components, you will see stuff that wasn't there before. Some of the items will be in subfolders, like "Games," which is under "Accessories." Double click to open any folder. Just uncheck the items you want to remove. There you have it. No more hidden programs!
good foundation and then keep up with the fun stuff.” “Well, how,” they ask, “do you get started?” “Easy,” I say, “as every journey starts, with the first step.”
The Foundation
Books are great, especially for getting a solid foundation – but, because they’re static, books are good only up to the day that they’re published. After that, you’re either waiting for a new edition of the book or stuck in a technological no man’s land. What to do? Fortunately there are several good web resources for looking at trends as well as keeping up-to-date on the latest gadgets and gizmos while you’re waiting for that update. Speaking of gadgets and gizmos, two of the must have sites to keep up-to-date with are 
If you notice, to describe these two sites, I pulled information from the invaluable Wikipedia website. 
“But,” you say, “there has to be more than just a couple of weblog sites and a user driven encyclopedia site.” Absolutely! For example, I get an e-mail update every morning from 
Finis
