
Defragmenter snap-in files have been de-registered Go to the Windows Update site to verify that you have all necessary updates. It is possible that a Windows update may fix your “disk defragmenter could not start” error. This may be able to fix errors that Windows own Check Disk utility cannot locate or fix, which may be the cause of defrag errors. You will need to identify the make and model of your hard drive and visit the manufacturer’s website or contact their customer support to download their diagnostic tools. Download your hard drive manufacturer’s diagnostic software If you have an external hard drive connected, disconnect it before trying to defragment your main hard drive. Google the name of any program you find, because there is a huge number of fake anti-spyware programs that actually put spyware on your computer. If you cannot defrag your hard disk, do a full malware scan using a recommended anti-virus and anti-spyware program like Trend Micro, Kaspersky, Auslogics Anti-Malware or Malwarebytes. It can cause problems seemingly unrelated to its activities. Check that the percentage of free space indicated is at least 15% – preferably 20%. Make sure you have at least 15% of the space on your hard disk free by going to Computer or My Computer, right clicking the icon for your hard disk and going to Properties. You will usually get a separate defrag error if you don’t have enough free space to defragment. Check that you have enough free space to defragment If your disk defragmenter can run in Safe Mode, this provides additional information to help diagnose what the problem is with a normal Windows start. Restart your computer and press F8 repeatedly after the boot screen to start Windows in Safe Mode. If No paging file is selected, try de-selecting it and seeing if that fixes your defrag error.



Click the Advanced tab again, and look for the Change button under Virtual Memory.

Go to Control Panel -> System -> Advanced tab and click Settings under Performance. Of course, if you can determine which program is causing the problem, you will still need to decide how to take action to fix the defrag error if you want to keep the program installed. If you still cannot defrag after all is done, try returning the system to an earlier time. Select the most recent restore point in the System Restore list and click Next. To do this, run System Restore – log on to Windows as Administrator and go to: Start -> All Programs -> Accessories -> System Tools -> System Restore. To find out if this is the case, roll back your system to the state it was before the change.
