That's a bit tooooo looooong.
Do you have any background apps running that may be interfering with it?
Try shutting down any non-essential applications before running Add/Remove
Programs to see if things speed up. If it does, then one or more of the
apps you shut down are the problem or at least a part of it.
If it has a minimal pickup in population speed, boot to Safe Mode to run
it and see if it runs a bit better.
If it populates as expected you need to take a good look at what's really
causing the issue, Safe Mode loads the minimal amount of drivers and
software that Windows needs to operate.
The first thing you should do is check the system for anything that may
be installed without your knowledge that shouldn't be. If all goes well
the next step is to check which of your apps and/or hardware "may" be
causing the problem.
How to perform a clean boot in Windows XP
http://support.microsoft.com/kb/310353/en-us
How to perform advanced clean-boot troubleshooting in Windows XP
http://support.microsoft.com/kb/316434/en-us
How to troubleshoot by using the System Configuration utility in Windows
XP
http://support.microsoft.com/kb/310560/en-us
--
Brian A. Sesko { MS MVP_Shell/User }
Conflicts start where information lacks.
http://basconotw.mvps.org/
Suggested posting do's/don'ts:
http://www.dts-l.org/goodpost.htm
How to ask a question:
http://support.microsoft.com/kb/555375