Windows after service pack 1 keeps uninstall information for all the updates in the C:\Windows Folder.These appear as $NTUnstall…

Depending on how many updates have you installed you might have anywhere from a couple to a couple of dozen of these folders.In order to save some disk space,you can delete these Folders.Doing this does not uninstall the updates,but will make sure that you can not uninstall them later…

In case you want to know exactly what uninstaller are you deleting ,you can go to http://support.microsoft.com/?kbid=<###> where <###> is the number listed in the name of the folder that you are deleting-remember don’t add the text “$NTUninstallKB” ,just the number after the prefix.Once you are satisfied,just select the Folders and press [Shift] +[Delete].

Now there are two ways in which to remove their references from the Add/Remove Program list.
Open the registry editor and navigate to HKEY_LOCAL_MACHINE\Software\Microsoft\Windows\CurrentVersion\Uninstall
Now ,select the key that corresponds to the update uninstall information that you want to delete ,and delete it.

Another way to do this would be to select the update in the Add/Remove Programs list and clicking Remove.Since you have already deleted the uninstall information,its obvious that you will get an error message that tells you that the update cannot be uninstalled,and you will get the option to remove the entry from the Add/Remove Program list.Just click OK and the entry will be removed.

Remember to check the show updates box,so you can see the installed updates in Add/Remove Programs.