Archived from groups: microsoft.public.windowsxp.perform_maintain (More info?)
If a volume's dirty bit is set, this indicates that the file system may be
in an inconsistent state. The dirty bit can be set because the volume is
online and has outstanding changes, because changes were made to the volume
and the computer shutdown before the changes were committed to disk, or
because corruption was detected on the volume. If the dirty bit is set when
the computer restarts, chkdsk runs to verify the consistency of the volume.
When Autochk runs against a volume at boot time it records its output to a
file called Bootex.log in the root of the volume being checked. The Winlogon
service then moves the contents of each Bootex.log file to the Application
Event log. One event log message for each volume checked is recorded. So
check the application event log.