I had this problem with at least 10 older PC's and win7. Win 7 installed correctly and the pc booted. Installed drivers and rebooted. Monitor turns off and never comes on. Force turn of pc by holding power button. Power on same problem. No VGA output. The PC's worked fine BTW after installing win XP. I've read somewhere that win 7 uses different boot resolution than other OS and hitting F8 on boot and selecting enable VGA mode fixed the problem on some PC's but not on all.
You are missing the most important question:
Do you get past POST? Usually when you turn on your PC all fans start running and after a few seconds you hear a beep. This beep signals that everything is ok with the hardware. If you don't hear that beep after turning on you PC your hardware is defect. Windows has definetly nothing to do with your problem as you don't have any output on your screen.
This is my experience anyway.I did worked in a PC repair shop for a while