My laptop was working fine, but I ran a comprehensive disk check (Stage 1--5) just for the heck of it. The check stops at stage 4 and gives no feedback. I let it sit there for 1.5 hours but it didn't give any more indications on the screen or move to stage 5.
The problem is: The chkdsk hangup prevents me from being able to log in. I can't get past it to use my machine. I haven't found a way to turn it off.
I opened the Windows command prompt using my system recovery disk and typed "chkntfs /x c:" but it did not stop the chkdsk from running again on restart.
Addendum: Now that I can login, I ran HD Tune Pro 4.01 and found that 1.5% of my blocks are damaged. It's time to buy a new HDD.