Try unplugging USB devices.
Also, I ran into this if I hibernate, remove power, upgrade the RAM and try to start up. It hangs big time. I never found a good fix but to put the RAM back to its original size, shutdown proper and then upgrade the RAM.
Dell Inspiron, dual core processor, 3 gb RAM, 3 months old, Vista Home Premium.
After restarting the laptop it was stuck in a "not responding" mode. The desktop looked fine but no response to any programs.
Shut down and starting up in safe mode- no change. I attempted to start up in "Last known good configuration". Ever since, all I get is a black screen with a white cursor.
I tried "safe mode with comand prompt", "Repair your computer", "Low resolution video"-same results. I can't even get back to the desktop or to some command prompt. Need help please