I was recently given an old Macbook (late 2006) and after upgrading it with 2GB of RAM and a 250GB hard disc I Boot Camped the crap out of it and installed Windows 7.  As expected pretty much everything worked after installation, something  I have come to expect of Windows 7, however any time I closed the lid of the machine or returned from sleep and hibernation the screen was black though the computer otherwise responsive.

It was only by chance I stumbled upon a now obvious solution to this, look at your screen under sunlight; under certain conditions you will see a picture still as the backlight is switched off.  Press the brightness buttons (fn and f1 or f2) and you will likely get your screen back, this even works at logon.  As for closing the lid, in power options set “Close lid” to “do nothing” and it will not switch off the screen.  Seems to work for me and hopefully will help anyone reading this blog in the same predicament.

Good luck.