When you install Service Pack 1 (SP1) on Windows XP, up to 3 folders are created:
- Random numbers, up to 20 characters, like 9650eb12e8b4d3547657, on the root of the volume that had the most free space.
%systemroot%\ServicepackfilesThis folder is required and must NOT be deleted. It contains updated files that are used by WFP and when you add or remove optional Windows components.
%systemroot%\$NtServicePackUninstall$This folder is created when you choose to archive the files required to uninstall the service Pack.
If you are sure you DO NOT want to uninstall the service pack, you may remove the folder. You can then remove the entry from Add/Remove Programs by deleting the entry from HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\Uninstall.
NOTE: After you delete the %systemroot%\$NtServicePackUninstall$ folder, you could use Control Panel / Add/Remove Programs to remove the registry entry. When you select the service pack Remove option, you will receive:
An error occurred while trying to remove Windows XP Service Pack n. It may have already been uninstalled. Would you like to remove Windows XP Service Pack n from the Add or Remove programs list?
If you press Yes, the option is removed from Control Panel / Add/Remove Programs.