I got the error message “Error 1721

I opened my Control Panel and selected “Add or Remove Programs.
I haven’t even picked a program to uninstall when I got the error message
Error 1721. There is a problem with this Windows Installer package. A program required for this install to complete could not be run.
Contact your support personnel or package vendor. How can I uninstall something if the program meant to do it is not installed?
If this is any help, I’m using a PC running in Microsoft Windows XP.

