It takes quite a bit of time depending on the size and speed of you hard drive, but it would be a good idea to use chkdsk to scan for bad sectors,(Areas of the disk that cannot be written to, or read reliably) not just file system errors. Sometimes hard drives develop small spots that are bad. This is no big deal because they can be mapped to a different area of the HDD. Scanning for bad sectors can mark these areas so your OS will not attempt to write to these areas again. That should prevent the disk from coming up "dirty" again. Maybe. Not guaranteed, but it sure can't hurt. File system errors happen when you shut off your system by force, before a file has a chance to get fully written to the disk, whereas bad sectors are bad spots on the disk that can't be read or written to reliably. The latter is more likely to cause your "dirty" issue.