Unable to install any guest VM

I have the latest macbook pro 17" and parallels 6. I had windows 7 installed and operating OK for several months, but this week I started getting the black screen upon starting windows. I followed various methods of repairing this and nothing worked. So I uninstalled parallels and VM. Now I have tried installing windows again and linux, but the install locks up at different stages each time and when I shut it down, I get the black(shaded) screen on the mac and have to do a hard reboot. Stuck for what to try next. Any help would be greatly appreciated. I am relatively new to the mac world.

 

I have tried reinstalling parallels, windows and linux several times each and different releases, with no joy. That is why I have posted. Are there files somewhere else in the system that may be conflicting? Each time I reinstall the install gets to different points then stops or fails. My business software runs in windows and that is the reason I need it. Otherwise I wouldn't bother.