Problem defragging with new partition

[3Bar_Mopar]

I added an empty partition to my HDD as drive "F". Now when I go to defrag I get a message "This version of Disk Defragmenter does not support running more than one instance.".
No "MMC" or whatever process is running twice either.
What am I doing wrong??

System is a Dell Dimension 3000 with 80GB HDD


EDIT:
I figured it out....I'm still new to this computer business...

I had to delete the partition, then create a new one as an extended drive, then make it a logical drive...formatted it again and everything is cool!