How to Uninstall Programs in Windows OS

Beginning with Windows 95, all versions of Windows have an Add/Remove Programs control panel that facilitates uninstalling programs. In DOS and Windows 3.1, you were required to manually delete the folders, files, and autoexec.bat and config.sys entries in order to uninstall a program. However, in Windows 95 and later, you are not required to manually uninstall programs.

Why Uninstall Programs in Windows?

You might want to uninstall software on your computer to free up hard drive space or if you are, for example, replacing one antivirus program with another.


Automatic Uninstall through Add/Remove Programs

The following instructions describe how to use the Add/Remove Programs control panel in different Windows Operating Systems:

Windows Vista

1. From the Start menu, select Control Panel.
2. In Classic View, double-click Programs and Features. If using the Control Panel Home view, under "Programs", click Uninstall a program.
3. Select the program you want to remove, and click Uninstall. Alternatively, right-click the program and select Uninstall.

Windows XP in the default XP view

1. From the Start Menu, select Control Panel.
2. Click the Add or Remove Programs icon.
3. Select the program you wish to remove and click Remove.

Windows 2000 and XP in Classic View

1. From the Start menu, select Settings, and then Control Panel.
2. Double-click the Add/Remove Programs icon.
3. Select the program you wish to remove and click Add/Remove.

Using the Uninstall program from the Start menu

If the program you wish to uninstall is not listed among the installed programs, there might be an uninstall program for that item on the Start menu. You can look for such an option by following the instructions below:

1. From the Start menu, select Programs or All Programs.
2. Find the folder for the program you wish to uninstall and highlight it.
3. In many cases, on the menu that appears, you will see an uninstall option.

If the program has neither a listing in the Add/Remove Programs control panel nor its own uninstall program, you might try installing it again, and then trying to uninstall it via the Add/Remove Programs control panel.

Using Uninstall Third-Party Software

Review list of free applications in the Software section of the site menu to choose the one that will automatically perform the software removal for you.


Manual Program Uninstall

Just because Windows XP has the Add/Remove Programs feature it doesn’t mean your application will appear in the list. Furthermore, even if it does appear, it’s no guarantee that the uninstall feature will work. When you run across one of these situations the items listed below will help in getting rid of the application. Be aware that these steps may not remove everything associated with the application and can impact other applications on the computer. Have a backup or restore point and use caution.

To understand the steps needed to perform to remove all (or most of) the traces of the program on the computer, you need to realize what is happening when you install the software.

There are several things that happen during the installation of a program. First, of course, is the copying of files to the specified program folder (which is usually somewhere inside the Program Files folder). Also some files such as shared libraries (.dll files) can be copied into a folder inside Program Files called Common Files and some files such as drivers or shared libraries (again) are copied into the ‘WINDOWS’System32’ and ‘WINDOWS’System32’drivers’ folders. After that the installer makes some changes inside the windows registry. The windows registry is a unified place where all the settings for programs and for windows itself are stored. The installer can make changes inside the registry for several reasons. For example if a shared library needs to be registered. Or if certain types of files need to be associated with the program being installed, so that the user could open them (e.g. if you install Microsoft Word, then you will be able to open Microsoft Word documents). After this is done, a key is added to the windows registry in a place where the Windows Add/Remove tool looks for installed programs. During the installation all these operations are logged in a special file (e.g. setup.log), and the installation program usually puts that file inside the application’s folder along with the uninstaller. When a user tries to remove a program through the Add/Remove tool, windows looks for the registered uninstaller inside the registry, and executes it. The uninstaller goes through the log file and undoes all the changes done during installation. That is, it deletes all the files that have been copied, all the registry keys the installer created etc.

However, if there is no log file, or if there is no record of the changes made to the registry the uninstaller might fail to uninstall the program, and it will stay there until it is removed by other means.

Note that the following operations should be performed with great care, since you enter to the sacred space of the Operations System, and improper deletion of the wrong entry might cause other utilities or operating system malfunctions.

• Find the directory for the application and delete all the files in the directory. Delete the directory.
• Open regedit and navigate to HKEY_LOCAL_MACHINE’SOFTWARE and find the folder for the application. Delete the folder.
• Open regedit and navigate to HKEY_CURRENT_USER’SOFTWARE and find the folder for the application. Delete the folder.
• To remove the application entry from Add/Remove Programs (if present) open regedit and navigate to HKEY_LOCAL_MACHINE’SOFTWARE’Microsoft’Windows’CurrentVersion’Uninstall and find the folder for the application. Delete the folder.
• Some applications have Services attached to them. If this is the case, navigate to HKEY_LOCAL_MACHINE’System’CurrentControlSet’Services, locate and delete the service.
• In Windows Explorer, navigate to the individual user settings and delete program references. Common places to check would be:

C:’Documents and Settings’All Users’Start Menu’Programs and delete relevant entries.
C:’Documents and Settings’All Users’Start Menu’Programs’Startup and delete relevant entries. C:’Documents and Settings’%YourUserID%’Start Menu’Programs and delete relevant entries. [Do this for each User ID listed]
C:’Documents and Settings’%YourUserID%’Start Menu’Programs’Startup and delete relevant entries. [Do this for each User ID listed]

If no entries were found in the previous step and the application launches automatically, navigate to HKEY_CURRENT_USER’Software’Microsoft’Windows NT’CurrentVersion’Windows and delete the entry.

Sources and Additional Reading:

http://kb.iu.edu/data/aixt.html
http://video.about.com/windows/Uninstall-Programs-in-WinXP.htm
http://www.theeldergeek.com/manually_uninstall_programs.htm
http://hubpages.com/hub/How-to-force-uninstall-a-program