Try going to GParted and right click on the /dev/sda1 partition. Then, choose check. Click apply and let GParted try to repair the partition.
Then go into Windows, and see if it will boot.
If this doesn't work, you will have to resort to a recovery: http://h10025.www1.h...e=null&key=null
Under that link, look at Starting a Recovery From the Hard Drive, and the Computer is Off.
Make sure you understand all of the directions before attempting the recovery. If you have any questions, post back here before going further.