Hotfixes will not install

I have been fighting with this problem for a long time. We have a Standard Windows 2000 desktop image at my company. Everything seems to work just fine, except when we go to Windows Update to download the latest hotfixes. Every time I have tried to get anything from individual fixes, all the way up to the Post SP2/Pre SP3 security roll-up it fails and gives me “The installation did not complete due to an unknown error.” I have tried several different things to get this working, all to no avail,including disabling antivirus, booting without any additional software loading up, etc etc etc. Anyone have any ideas or experienced this as well?