What is $Windows.~BT folder and How to Delete It?

While Windows 10 has not major hard drive requirements, nor high-end hardware, it’s just 16GB for 32bit OS and 20 GB for 64 Bit version, but this whole upgrade process leaves a chunk of temporary windows files which eats up a good value of your free space in hard drive. This folder appeared when Windows 10 up-gradation has started. There will be 2 folders i.e. $Windows.~BT, and $Windows.~WS which shall be used by windows for upgrading to Windows 10. However $Windows.~BT is the folder where Windows backup your previous OS whether it would be Windows 7 or Windows 8. Don’t touch these folders till the time you upgrade to Windows 10.

What is Windows-BT folder and How to Delete It

When you have upgraded to Windows 10, you’ll find that $Windows.~BT is consuming a good chunk of your drive space. Now there arise a need to getting rid of these folder, and you just can’t use Delete option for this folder as Windows won’t allow you to delete this easily for obvious reasons. Also you’ll find a windows.old folder, which is a copy of system files of previous windows.

Please Note: If you deleted $Windows.~BT, and $Windows.~WS, you’ll not be able to roll-back to previous windows if required. Also before the upgrade, windows 10 upgrade files are placed in this folder so you can upgrade from 7/8.1 -> 10. So deleting it will cause issues (or a re-download) of the Windows 10 upgrade files.

What is $Windows.~BT folder and How to Delete It?

Solution 1

Regarding deletion of $Windows.~BT or even Windows.old folder, procedure is fairly simple:

  • Press Windows key + R (when being on desktop)
  • When “Run” command box appears, type:
  • cleanmgr.exe
  • Hit Enter.

This shall open a dialog box of Disk Cleanup. Choose C:\ or the drive where you have these folders.

Disk CleanUp Windows 10

After Disk cleanup is done scanning, Click “Clean Up System files“. Now it’ll again ask to select Drive, choose same drive and click “OK“.

Disk cleanup old Windows files

Now, you’ll be presented with choices to clean “Previous Windows Installations“, “Temporary Windows installations files“. Choose the options which shall help you gain back a big chunk of hard drive space back. Click Ok and let it delete those in background.

Also on Trouble Fixers:

You’ll find that “Windows.old” folder is no more, but chances are that you’ll still find $Windows.~BT, and $Windows.~WS in your hard drive. Then you need to follow “Solution 2“.

Solution 2

If Solution 1 doesn’t helps you, then you’ll need to take complete ownership of $Windows.~BT folder.

  • Right click on $Windows.~BT folder and choose Properties.
  • Go to Security Tab and Choose you current user with which you’re logged in.
  • Click Edit. Again choose your current user with which you’re logged in your computer.

Taking ownership of Windows-BT folder

  • Click Check box of “Full Control” and Click Apply and OK.

Taking Full Ownership of Folder

  • Again Click OK to close last dialogue box. Now you’ve full ownership of $Windows.~BT folder.
  • Now right click on the folder and simply delete it.

Microsoft recommends that you should keep this folder, in case you never know what happens wrong with software’s, and you might need to roll back to previous windows. For same reasons, windows.old folder must not be deleted until you really have a crisis of space in your hard drive.



  1. I have been regularly checking the $Windows.~BT folder on the C drive to see if Microsoft was still trying to dump more Windows 10 prep files. After this last Windows Update, went to check the folder and it is GONE. Any idea what happened and should I be worried? Is there a fix?

    • Yes, on Windows 10, after last update, it has disappeared for me too. Maybe Microsoft has cleaned it up to save disk space. I welcome this change.


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