Had this error while trying to update a Windows 2000 SP4 test box. As it’s a test box, it has the bare minimum installed.
Microsoft’s solution?
- clean the Internet Explorer cache
- Delete some files in the WindowsUpdate directory
- Delete some DLL’s.
None of those worked.
The actual solution which worked for me? Install Internet Explorer 6.
Other things I could have tried? Autopatcher, which I wrote about here. Except that Autopatcher no longer supports Windows 2000. 
Or apply the patches one by one, after running an MBSA scan? Maybe.
IE5? Well I did say it was a test box.
i have error while updating my win2000 sever its gives error number 0*800c0002,ihave internet explorer 5 version,plz help
Well just upgrade to IE6, and that might fix it for you.