I too have uninstalled and reinstalled Adobe Reader 8.1.whatever... each time it tells me the install was successful but when I try to open it I get an error message - Adobe reader has quit working. I use XP.
What is frustrating was I was about to read a pdf and was prompted to upgrade. I chose to do the upgrade thinking I would read it in a few minutes after upgrading. Now I can't read a thing and it has been over a day.