My computer crashed earlier today. Restart button didn't work so I held down the power button to turn it off then booted it again. Tried to 'start Windows normally' and ended up with the Startup Repair tool. It ran for two hours, I got impatient and turned it off and on at the wall. It's now back at the Startup Repair tool... Should I let the tool do its thing? How long is too long? Should I be looking for a computer repair shop?