If you open Device Manager, specific device and you read info about files which are body of driver sometimes you shall find entry like this one: "C:\windows\system\vmm32.vxd (ntkern.vxd)" This means that device is not using normal driver file but just generic"vmm32.vxd" slower driver. Some say that this setting causes system crashes and lock-ups and lowers system stability. to fix this bug, following files have to be installed to both "x:\windows\system" and "x:\windows\system\vmm32" folders: vc