I had a similar problem. Black screen after Bios menu but before Windows 7 logo. Couldn't use F8 for advance options because it just took me to F12 boot menu. Repair didn't work, neither CMD boots commands.
Here's what I did. I installed a new operating system on my primary hd, I didn't uninstall windows. This way I could see the menu to pick my operating system and finally use F8 again. I just picked start with last good option(Or whatever it's the name) and it fixed.
I hope this help anyone else stumbling upon this problem using google.