So I had a bit of trouble with some bootcamp machines running the Nvidia GeForce 9400 in both Windows 7 & 8. Intermittently they would boot without video. Not right away, initially, it would show video during initial startup. However, as it got to the login screen, the screen would go distinctly blank. I had installed the latest drivers from apple (Bootcamp Additions), even tried 3rd party drivers. Nothing solved the problem, the best I could do was reduce the frequency of occurrence. I was about to resign just to deal with it when a came upon GeForce Experience. This is a software suite to optimize Nvidia graphics cards for gaming. The 9400/9400M is certainly not a gamer card, but that doesn’t stop the Experience from identifying and installing proper drivers before reporting that no gaming optimizations are available. Despite it’s inability to enhance my gaming, the tool certainly resolved all my driver issues. I cannot recommend it highly enough. Give it a go if your Nvidia drivers are making you crazy.