Solution to ‘Disk Defragmenter could not start’

To solve this problem go to START > RUN and write this regsvr32 dfrgui.dll do the same thing to this instruction regsvr32 dfrgsnap.dll

A letter of succeed will appear, now show the hidden files and open this directory C:\windows\inf search for this file dfrg.inf, right click on it and click install.

Enjoy…