Blue Screen often occurs when Windows detects an error with your Windows operating system or with your hardware components. Try to check the cables and then perform a system scan using Start > Run > cmd > sfc /scannow. You might need the Windows install disc. Try to swap the memory modules in case you have more than 1, and perform a clean of the registry items with CCleaner.
You can run sfc /scannow from Safe Mode. It's recommended this way to avoid other possible restarts.