where <drive> is c, d, e, or whichever one you want to defrag. You
cannot NOT specify a drive letter and you can specify only one drive, so
you will need as many tasks to do defrag as you have partitions (i.e.,
drive letters) unless you write a batch file with multiple calls to the
defrag program, each with a different drive letter, and run the .bat
file in the scheduled task.