May I throw my two cents in......
Go to
www.download.com, tucows.com or zdnet.com and search for a registry repair tool. They are there, some are free, and they work.
I use a commercial version called Fix It Utilities System Suite.
Broken links in the registry can hang up a machine quite easily. Uninstalling software sometimes is not complete.
Also look for a registry defrag program. Please don't confuse this with the normal hard drive defrag program.