If you are having problems with your Windows 7 blue screening (often called BSOD or blue screen of death) then this new Windows help article may help you in resolving it:

Resolving stop (blue screen) errors in Windows 7

It covers troubleshooting tips if you can or cannot start Windows and hopefully will get you up and running again.

Stop errors (also sometimes called blue screen or black screen errors) can occur if a serious problem causes Windows 7 to shut down or restart unexpectedly. You might see a message that says, "Windows has been shut down to prevent damage to your computer."

These errors can be caused by both hardware and software issues, and it can be difficult to troubleshoot the problem.

Rob