Can't update Adobe Reader, Java, etc. Using XP

Hi, I'm new to this forum, but I need help. I have a problem that I first noticed as Internet Explorer hanging when I tried to open a pdf file. When I tried to update Adobe Reader, it said that a file was in use and it could not proceed. the same thing happened on a number of other programs, such as HP software updates. I have SpyCatcher and the Symantec security suite as well as GhostSurf running. I'm running Windows XP sp2. I've tried running is safe mode, but the same probelm exists. I have a few others symptoms that may or may not be related, such as sometimes not being able to bring back my screen after it goes blank on its own. Has anyone had a similar experience? solution?

While it doesn't generally seem like malware I suspect there's a possibility of this. So I suggest you post a HijackThis log and post it over at that forum.