The Disk Defragmenter is not installed on your computer what is that

The Disk Defragmenter is not installed on your computer. To install it, double-click the Add or Remove Programs icon in Control Panel, click the Install/Uninstall tab, and then follow the instructions on your screen.

To fix this problem, do this:

Start --> Run --> regedit

Then follow this directory:

HKEY_LOCAL_MACHINE

SOFTWARE

Microsoft

Windows

CurrentVersion

explorer

MyComputer

DefragPath

Then change the value default from the right to %systemroot%\system32\dfrgui.exe

Then restart you computer.

Enjoy…