6.6 doesn't work on win 7. Why?

win 7 pro
Defrag gets stuck and stops working. When you stop the defrag, it slows the computer way down.

Anonymous2020-08-09T12:35:53Z

what is 6.6???
is your computer 32 bit OS or 64 bit OS

2020-08-08T18:20:45Z

what is 6.6?
if defrag won't work, there is a problem with your hard drive.
you need to run chkdsk with recovery option to fix it.