Windows 7 Defrag from command line does not work

Question

We are running Windows 7 in a virtualized environment. When running windows defrag using schedule or from command line, it does not work. The command that I am executing as administrator is
C:\Windows\system32>defrag /c
Microsoft Disk Defragmenter
Copyright (c) 2007 Microsoft Corp.
It displays the above message and exits back to the command prompt. However if I run the command defrag C: it does work. Defragmenting from the GUI works as well as long as both the disks (C: and System Reserved) are selected and when I click on
Defragment disks, works fine.
I am concerned about defrag running from the task scheduler with the command "defrag /c" (auto scheduled using Configure Schedule... from Disk Defragmenter) does not work and the system never gets defragmented automatically.
This happens only with some of the windows 7 VM's that we have.
There are no entries in Event Log that point to the defrag (using task scheduler). Any ideas what may be going on?

Answer 1

Hi,
Could you defrag as below method:
1. Open Disk Defragmenter by clicking the Start button. In the search box, type
Disk Defragmenter, and then, in the list of results, click
Disk Defragmenter.
2.Under Current status, select the disk you want to defragment.
3.To determine if the disk needs to be defragmented or not, click Analyze disk. Administrator permission required If you're prompted for an administrator password or confirmation, type the password or provide confirmation.
Once Windows is finished analyzing the disk, you can check the percentage of fragmentation on the disk in the
Last Run column. If the number is above 10%, you should defragment the disk.
4.Click Defragment disk. Administrator permission required If you're prompted for an administrator password or confirmation, type the password or provide confirmation.
For more information, please read this article:
Ways to improve your computer's performance
http://windows.microsoft.com/en-in/windows/improve-performance-defragmenting-hard-disk#1TC=windows-7
Meanwhile, read this article:
Defrag from the Command-Line for More Complete
Control
http://technet.microsoft.com/en-us/magazine/ff458356.aspx
Karen Hu
TechNet Community Support