I'm guessing that this is a hardware manfunction of some sort.
After my computer has been on for a while it will lock up with no applications running. It will try to load an application but will appear to be using all available resources (hour glass on screen). In task manager, CPU usage is 0 and memory use is very low (<20%). It is working fine right now as I'm typing this, but will freeze up if the computer is left on for perhaps an hour.
After it freezes are there any diagnostics that I can do to check for a hardware problem? I'm thinking motherboard/capacitor, etc.