The following article explains how to repair defragment in Windows Vista. It will also mention alternatives in case the repair does not succeed. The following error messages are symptomatic: “The Disk Defragmenter is not installed on your computer” or “Windows cannot connect to the Disk Defragmenter engine”. The suggest help topics do not help in this case.

The first thing that can be done is to register two dynamic link libraries (dlls) again. This can be done by opening a command prompt as an administrator and typing in the following commands:


regsvr32 dfrgsnap.dll
regsvr32 dfrgui.dll


You might need to switch to the system32 directory first in the command line using cd /windows/system32/.

The second option is to reinstall the defragment tool completely. Locate the file dfrg.inf in the /windows/inf/ directory. Right-click it and select Install from the menu.

Alternatives To The Windows Defragmenter:

There are two possible alternatives. You can try and start the Dos defragmenter by typing in defrag.exe or install a third party disk defragmentation tool like disk defrag.