I would also check the video card drivers. The best thing to do is uninstall the video card drivers, force the display driver to Standard VGA, then re-install the drivers from the manufacturers website.
Next, run a memtest on the memory to see if it passes.
Then check the hard disk by going to Computer > Disk Drive > Right-Click > Properties > Tools > Check now...
If no issues arise in these test. Try setting Windows Automatic update to once a week or never (temporarily). Also, set your power profile in Control Panel > Power Options > Maximum Performance. This will disable some of the more sensitive power states. Link Power Management is especially sensitive and can cause the hard drive to hang.