SYMPTOMS:
Although Windows may seem to shut down correctly, ScanDisk may run the next time you start the computer.
CAUSE:
During the shutdown process, the contents of the virtual cache are written to the destination device. If the destination device is an Integrated Drive Electronics (IDE) hard disk, data may be written to the hard disk's onboard cache but not to the disk itself. When this occurs, the data is lost from the cache when the computer turns off.
To disable Scandisk on startup:
Go to Start > Run.Type msconfig and hit enter.
Click Advanced, and select the "Disable Scandisk after bad shutdown" option.
Click OK,OK and then Yes to restart your machine.