Great support from Microsoft
 

Yesterday I upgraded to Office 2000 SP-3. Today I discovered that my Excel
2000 spreadsheets with the Solver referenced in VBA no longer worked.

Digging through this group I found a hotfix (see KB821430) that exactly
described my problem. But it was not provided at the MS support site.

I dreaded calling MS support...

But a real human being answered the phone after a few button presses, got
the issue, promptly transferred me to another human being who promptly sent
me the hotfix at no charge. Probably took a total of 10 minutes from dial to
install.

Well done!