[AgentZero]

OK, well I cleared out everything except AV, Firewall & video drivers, but it doesn't seem to have helped much. I've also got rid of all my anti-virus programs except one.
As for the Processes, most of the time it seems to just be System Idle Processes taking up 99%, but CIDAEMON.EXE and cisvc.exe occassionally jump up to around 20%.

The biggest problem, for whatever reason, seems to be opening folders. If I launch a program from the desktop, it seems to work OK, but a lot of the time when I try opening My Computer, using the Start Menu, or opening a shortcut to a folder from the desktop, it either takes a very long time, or nothing happens at all.