Installing/unistalling problems in Windows XP

I am have some problems in WinXP Service pack 3 in that I cannot install Windows live essentials properly It install almost completely then rolls back. If I look at the Add or Remove Programs screen it shows up but I cannot uninstall this program either. It appears to be stuck.

In addition will working on other issues I have found an instance of AVG on my computer. I had thought that I uninstalled this also as it doesn't show up in the Add or Remove Programs screen and it apparently does run in the background. I have no way to view it or shut it off. I am currently running Microsoft Security Essentials now. Can these problems be related?

Kevin