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What Is The $WINDOWS.~BT Folder On My Hard Drive?

If your C drive (or whichever drive it is you’ve installed Windows to) is taking up more space than it should even though you haven’t installed anything new, or added any large files, you might be wondering what’s going on. For anyone running Windows 7, 8/8.1/10, this sudden space consumption can be as high as 6GB and it might be attributed to a folder called $WINDOWS.~BT that exists on your drive. Here’s a look at where that folder came from, why you may or may not need it, and if it’s safe to remove from your system without causing any trouble.

Where Is The $WINDOWS.~BT Folder Located?

The $WINDOWS.~BT folder is hidden. It exists at the root of the drive you’ve installed Windows to. To see it, enable viewing hidden folders.

$WINDOWS.~BT folder

What Is The $WINDOWS.~BT Folder?

The $WINDOWS.~BT folder came from Windows, or more precisely a Windows update. It contains the files needed to upgrade to Windows 10. These files were gradually downloaded over time. The folder will have been created some time around the Windows 10 release (July 29). It may have been created before the release date so as to relieve Microsoft’s servers of the stress of too many downloads the day of release.

The folder on my drive was created on July 10, 2015 and is almost 6GB. Inside is a Setup EXE file which, if I were to run it, would initiate the Windows 10 upgrade. It’s worth mentioning here that if you have the KB3035583 update installed, files for upgrading to Windows 10 will download to your hard drive and this folder will be created. It won’t matter if you reserved a copy or not, or if you reserved a copy and you’re still in queue for the upgrade, this folder will exist and files will be downloaded to it. Resistance is futile (I’m kidding, read on to see how you can get rid of it).

$WINDOWS.~BT properties

Can I Delete The $WINDOWS.~BT Folder?

For Windows 7/8 users, ff you aren’t planning on upgrading to Windows 10 you can delete this folder. The real question is, how to do that? Will a simply Delete function work? In theory it should. It’s a folder that you can just Shift+Delete however, since it’s tied to an update process, it will simply appear again. What you will end up with is several failed update attempts in your update history. I’ve got one for every day of the week.


I deleted the folder a long time ago but it repopulated again and Windows keeps trying to upgrade to Windows 10 despite my not having reserved a copy. If you’re fed up of this and want to free up space on your drive, you need to uninstall the KB3035583 update. To do so, go to Windows Updates and click on ‘Installed Updates’.

Windows Update

Both Windows 7 & 8 users, find the update called KB3035583 and uninstall (and hide) it. Additionally, Windows 7 users need to uninstall and hide the update KB 2952664. Windows 8/8.1 users need to uninstall and hide update KB 2976978. These last two updates are responsible for checking whether or not your system is compatible with Windows 10 but they’re also downloading Windows 10 in the background.

KB3035583 - uninstall

You can now delete the $WINDOWS.~BT folder on your hard drive. You will need Admin privileges to do so but we’re assuming you already have those if you were able to uninstall the KB3035583 update. If you’re having trouble deleting the folder, try using disk clean up.

Hit Windows+R and type %windir%\system32\cleanmgr.exe in the run box. Select the Windows drive and allow it to scan the drive. Once it’s finished scanning, click the ‘Clean up System files’ button and allow it to scan your drive one more time.

Disk Cleanup for (C)

Once scan is complete, look for and check the ‘Temporary Windows installation files’ option. It will be pretty big in size. Begin the clean up process.

Disk Cleanup $WINDOWS.~BT

What’s In The $WINDOWS.~BT Folder On Windows 10?

The $WINDOWS.~BT folder, whether it’s on Windows 7 or 8/8.1 contains files for upgrading to Windows 10 but why does this folder exist in Windows 10? In Windows 10, the $WINDOWS.~BT folder contains your old Windows installation. Bear in mind that once you upgrade Windows 7/8 to Windows 10, you have a one month window to downgrade your installation. The $WINDOWS.~BT folder in Windows 10 contains files that will assist in the downgrade process. It also contains logs and other files related to the upgrade. If you’re one hundred percent sure you will not need to downgrade to your older Windows installation, and Windows 10 is working great for you, you can go ahead and delete this folder much like you would delete any other folder. You can also use Disk Clean up as described in the previous section to delete this folder in Windows 10.

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