Could be a number of things. If it's hardware it may be your sound and graphics is not up to the games. Try turning off any non-vital background progs. Also go to device manager (right-click My Computer for System Properties, then Hardware), go to IDE ATA/ATAPI Controllers, open and right click drives, adavanced, and check box for Transfer Mode to DMA if available. Also go to System Properties/Advanced/Performance Options and click 'change' and change your paging for each drive to twice ram amount, ie; if ram is 256 then at least double it.