The snap-in is not created

In my Disk Defragmenter Program I am having a critical problem.
The screenshot attached below says details about the problem. The error message is;
“Snap-in Creation Failed.
The snap-in is not created; it may not be installed properly.
Name: Disk Defragmenter
CLSID:{43668E21-2636-11D1-A1CE-0080C88593A5}”

I don’t want to reinstall the windows. It’s for me troublesome. Is there any alternative way?
Please help.
