Reference number: CH000664

Cannot defrag drive because it is locked by a disk utility.

Question:

Cannot defrag drive because it is locked by a disk utility.

Cause:

This issue is caused when other programs or files are being accessed in the background as defrag is being ran. If defrag detects any type of a file change while being ran it will restart.

Answer:

To resolve this issue make sure all other applications are closed and that any TSR programs are also closed. Additional information about TSR programs can also be found on document CHTSR. If doing this does not resolve your issue you can also run defrag through Safe Mode. Additional information about how to run defrag through Safe Mode can be found on document CHSAFE.