1. Power off, remove the AC cord and then unplug ALL USB things. Apply AC, try again.
2. No go? Try the generic reset (safe, takes 2 minutes.) Unplug the AC from all things, press and hold the power button on the PC, release, apply AC to PC, display and try again.
After this we are into the usual PC repairs you read about on the web.
I have an emachines computer about 4 to 5 years old, with windows vista on it. When I turn it on it beeps twice, the monitor tries to come on, and then the monitor goes into power saving mode. I don't think the pc loads windows. Any suggestions?