and based on the assumption that nothing physically has changed on the system since you last installed the game...
Go to this link and follow the instructions:
http://tinyurl.com/3e4bhy
Additionally,
Download and install the latest BIOS for your motherboard and the latest driver for your video card. Both can be downloaded from the respective manufacturer's web sites.
Try adjusting the Video Hardware Acceleration. Typically accessed by going to Display Properties, Settings tab, Advanced button, Troubleshoot tab.
There is the possibility that the error is being caused by a CPU that is overheating or getting ready to fail.
I hope this helps.