Reinstalling Disk Defragmenter will resolve the problem. Click Start, Run and type:

rundll32.exe setupapi,InstallHinfSection DefaultInstall 132 %windir%\inf\dfrg.inf

Press ENTER

See also:

Error: "The Disk Defragmenter is not installed on your computer"
http://www.winhelponline.com/articles/60/1/

--
Regards,

Ramesh Srinivasan, Microsoft MVP [Windows Shell/User]
Windows® Troubleshooting http://www.winhelponline.com


"Biochemist" <Biochemist@discussions.microsoft.com> wrote in message news:44966B5A-B777-4C61-A33C-BD94AC7D77C8@microsoft.com...
When I go to my computer then right click on the usb external hard drive,
then select properties, select tools, then select defrag radio buton. I
recieve a message that Defragment not installed on this computer, however I
know that it is, please help.
Thanks