Having looked about the net a bit. It could be drivers, Page file or Ram.
Drivers - Try updating some of the older ones
Page File - Right Click on my Computer , Properties, Advanced, (Under Performance) Settings, Advanced Tab, (Under Virtual Memory) Change, At the top select the C:, Chose Custom Size and set min to 1024 and max 2048 (Please note this does depend on your hard drive, If 20 GB or over this should be fine.) Chose Set, then click ok. and ok and ok again.