Why does Defragment Hard Drive sometime fail to run?  What do I do?

Defragment Hard Drive will not run if the files it is attempting to compact are in use.

Please re-schedule Disk Defragmentation at a time when the files are not being used. This means that you should not run disk defragment at the same time you are running anti-virus disk scan, or any backup or any indexing system.

Defragment Hard Drive will not run if any hard drive errors or file structure errors are found.

Please run Scandisk/ CHKDSK first before you run Defragment Hard drive.