MacBook Pro windows update closed laptop...

Hi, I clicked shut down on my laptop when it was on Windows 7, and it said it was updating. I closed my laptop and then when i opened it later on in another location, it was still updating. It finished and shut down. Then I started it back up and went to the Mac side of my laptop to do some work. Now I'm back home and I wanted to restart in the Windows part, but all I get is a white screen.. help?