For users of version 5 
This can be fixed by running the appropriate patch file linked below. 

-)If you are currently using SystemSuite 5, please download this file:


-)If you are currently using Fix-It 5, please download this file: 


Once you have downloaded the file, just double click to run it. Then reboot your machine and try running JetDefrag again. 

For users of version 4 

Please try the following steps: 

From the Windows Start button, click Run. Type chkdsk /r and press the Enter key. 

You will be prompted to allow chkdsk to be scheduled. Press "Y" to do so. 

Reboot your computer. Chkdsk will scan your hard drive during the bootup process. 

When Windows has finished loading, try running JETDefrag or the All-In-One Wizard again. 

If JETDefrag continues to give you the error message, go into Internet Explorer and delete the Temporary Internet Files, cookies, and history. Then try running JETDefrag again."