Note: This article is courtesy of a conversation I had yesterday with my good friend Ross, who runs the excellent SimpleHelp blog that you should check out (and subscribe to).
Set Automatic Defrag Options
Launch Disk Defragmenter by typing dfrgui into the start menu search or run box (or you could just search for defrag in the start menu or control panel)
Once you are there, you will notice the new “Select volumes” button that wasn’t there before Service Pack 1:
This will launch a dialog where you can choose which drives should be automatically defragmented at the scheduled time:
Of course, you can also use this same new feature to manually defragment all your drives at once, instead of having to use a batch file.
There’s really not much to it, is there?
Note: Vista most likely already scheduled all your drives to be defragmented by default, or at least it did in my testing.