Windows 2000 appwiz.cpl didn't open

This is an old old problem, but appwiz.cpl (Add/Remove Programs Wizard) didn't run on Windows 2000 Professional.
This post resolved it:

I had all these problems listed above-- I did this and it worked first try

Start a command session by going to Start, Run and typing
cmd
Enter each of the following commands (click OK to each confirmation that appears):
regsvr32 mshtml.dll
regsvr32 shdocvw.dll -i
regsvr32 shell32.dll -i
Close the command session by typing
exit

Then start add/remove from control panel -mine worked right away