Windows Vista now comes with an automatic disk defrag tool that is enabled by default. Specifically, it is set to run at 1am every Wednesday. You can disable or modify this by performing the following steps:

1) Click the “Start Orb”
2) Click the Control Panel
3) Click “System and Maintenance”
4) Finally, choose “Defragment your hard drive” from under “Administrative Tools” (at the bottom of the menu/list).

Or, my favorite/quick way:

1) Press the “Windows Button” on your keyboard, type “Disk Defrag” and press enter.

Again, the power of typing what you want to run in the search field at the bottom of the start menu is a huge time saver. I’ve read a few books now that talk about “Run” missing from the start menu as though it is a horrible thing, with instructions on how to get it back. There really is no need—the search field does the job better than Run ever did. And if you really want run for any reason, pressing “Windows” and “R” together still does the trick.

But I digress…

The defrag menu is as shown in the image below. You can simply uncheck the “Run on a schedule” box to disable it, or pres the “Modify schedule” button to pick a new time.

But that’s for users. What you need is a nice command line interface and you’ve got it here...