This is one of the more bizarre issues I've seen. One of the guys at my company has Vista on his laptop which worked just fine until earlier this week. All of a sudden, everything would run really slowly, but only intermittently. AFter playing with it a bit, it seems like windows is sometimes trying to access the C: drive like a network share or something.
In Outlook or Word, for example, it'll hang with a message in the toolbar of "Contacting C:\Users[username]\AppData...". This will usually eventually timeout, with the program saying it couldn't find the relevant file. (Either a Word doc or Outlook PST). And then sometimes if you try it again it'll immediately pop up and work like normal. IE exhibits similar behavior, but it's harder to tell what it's actually doing. But for example I'll open up one IE and it just hangs, but I can wait a little while and start another IE and it'll immediately work fine, while the first one is still hung.
Does anybody have any idea what's going on? It's got Norton on there and it reports no problems. I've tried stopping just about every service and it still seems to do it. It did seem to work better in Safe Mode, but I can't be sure because of the intermittent nature of the issue.
I'm also a programmer, not a Windows admin, I just have to play one because this is a tiny company, so I could be missing something really basic.
ETA: UAC is running.