I get various of these symptoms - not always all of them, it happens most often right after I have rebooted.. I do have a gut feeling that if I reboot and don't come to the computer for an hour or so there will be no problems.
WIndows XP on a software development machine - which has a large number of apps installed. Norton Internet Security - no attached server for running apps, 2 NASes and a Drobo for backups
1. Quick Launch taskbar locked and none of the icons work, an hourglass displays
2. Opening folders from the desktop - the folder opens and sits there without any icon displayed, and is not responding - the folders should contain shortcuts to programs on local drives
3. Cannot run any apps from the desktop or start menu
4. My Computer is not responding and I cant see the drives
5. Despite this - if I start applications e.g. Firefox -- from DOS and not the taskbar, then they run ok.
It used to be that if this happened, I could terminate Explorer from task manager and restart it and 90% of the time the problems would disapear, 10% I would have to reboot, now that's more like 50/50%
I've had this problem on and off for a year - but not enough to concern me, but in the last few weeks it has now become a very routine almost daily issue that affects my productivity. Some days- I'm lucjy and I have no problems.