Add/remove programs doesn't work after update

Under win2000 sp4

I recently used Windows Update, and I have 40 subs in \winnt
with names $ntuninstall*.*

The "Add/Remove programs" (mshta.exe, as it shows in the
task manager) doesn't work anymore.

I've read somewhere that every update has an entry in
"add/remove". Is it possible that the list has become too
large, and that that freezes mshta.exe, or should I remove
the update pertaining to this program ? How do I identify
that one from the 39 others, and how do I uninstall it ?

I should add that there are 2 versions of mshta.exe in my
computer:
the older one is in \winnt\system32 and in \winnt\dllcache,
the newer is in \winnt\servicepackfiles\i386.
I tried replacing the older by the newer AND vice versa, but
that didnt't change a thing.