Error Message "Windows Cannot Defragment This Drive now Because It Has Been Locked by a Disk Utility" When Using Disk Defragmenter

When you attempt to run the Disk Defragmenter tool in Microsoft Windows Millennium Edition (Me), you may receive the following error message: NOTE: This behavior can occur whether you start Windows Me in Safe mode or Normal mode.

This behavior can occur if you have the Speed Disk utility from Norton System Works 2000 installed on your system. This utility, if running in the background, blocks the use of the Disk Defragmenter tool.

This error can also occur if the file allocation table (FAT) table is damaged.

To resolve this behavior, if you have System Works, you must quit the Speed Disk utility and restart the Disk Defragmenter tool.

To repair the file allocation table, follow these steps:

1. Restart your computer in DOS using the Windows Me Emergency Boot Disk (EBD).
2. At the command prompt type scandisk, and then press ENTER.
3. The following message appears:
   The file allocation table FATs on the disk drive do not match. Scandisk has determined that copy 1 is the best copy. If you choose fix it, scandisk will replace copy 2 of FAT with copy 1.
4. Press Y to anwser Yes to the message.
5. Scandisk will replace your damaged FAT with the undamaged copy 1 of the FAT.

After Scandisk finishes repairing your hard disk, remove the Start up disk, and then restart your computer.

When Norton System Works 2000 has just been installed, the preceding behavior does not occur. When Speed Disk runs, however, the preceding behavior occurs.

The reverse situation (the Disk Defragmenter tool running in the background) can block the use of the Speed Disk utility. When you attempt to run the Speed Disk utility, you may receive the following error message:

Either of the preceding situations can also result from the overlap of scheduled tasks.

The third-party products that are discussed in this article are manufactured by companies that are independent of Microsoft. Microsoft makes no warranty, implied or otherwise, regarding the performance or reliability of these products.


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