I saw other entries where people have been told to:
Click Start, then Run (Search In Vista)
Type cmd, and click Ok
At the prompt in the command window that opens, type fsutil dirty query ?: and press Enter (Where ? is the letter of the drive to queried)
I've tried this, but it won't let me because it says that I'm not an administrator, even though I'm the only account on the computer, and I am the administrator. The prompt window just says Users/user.
Is there anything i can do to change it?