If you chose the option to be able to uninstall a Windows 2000 Service Pack, you might want to remove the uninstall folder and the Control Panel / Add/Remove Programs entry, once you are convinced that the service packs has not introduced any unwanted behavior.
To accomplish this task:
1. Delete the %SystemRoot%\$NtServicePackUninstall$ folder.
2. Use Control Panel / Add/Remove Programs / Windows 2000 Service Pack 1 and press the Change or Remove Programs button. You will receive a message that the service pack can not be uninstalled, offering you the option to remove the entry from the Add/Remove Programs list. Reply Yes. Alternately, you can use Regedt32 to navigate to HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\Uninstall and delete the Windows 2000 Service Pack 1 key.