How to Safely Delete $WINDOWS.~BT and Windows.old Folders

Well I upgrade my Lenovo ThinkPad W520 from Windows 8 to Windows 10 Release Preview. The upgrade worked flawlessly (thank you Microsoft!). So I’m checking out my new digs on the new OS and opened up Windows Explorer. Very nice! The new ribbon feature add great additional functionality to the tool. But I saw that there were a few new folders added ($WINDOWS.~BT and Windows.old). Naturally I assumed that it was the folders used in upgrade process. So I decided to continue and investigate more of the new functions of the OS.

In the end, the final verdict was this build was Rock Solid!!

So the next day back to work I needed to open Windows Explorer to copy a file and the $WINDOWS.~BT and Windows.old folders were still there. I looked in the contents and it didn’t seem to be a lot there. So I checked the properties of the $WINDOWS.~BT folder and was quite surprised to find out that it took almost 10 GB of space. Did the same for the Windows.old folder and it was a lot more (25 GB). WOW!!



So I attempted to delete the $WINDOWS.~BT folder directly since I was Administrator on my machine, to no avail, So I will spare you the ugly details of changing owner from TrustedInstaller to Administrator (or whatever account). Then reset permissions, yada yada… because there is a MUCH easier and safer way to remove these folders.

NOTE: If you do nothing for the next 30 days, Windows 10 will delete these files automatically for you.


1. Press the Windows Key and type Disk. That should display Disk Cleanup


2. Click Disk Cleanup.

3. In the Disk Cleanup: Drive Selection dialog box, select (C:) and click OK.


4. In the Disk Cleanup for (C:) dialog box, click Clean up system files.


5. In the Disk Cleanup: Drive Selection dialog box, select (C:) and click OK.

This is not an error. The first selection was for your personal files/items, this selection is for the system files




6. In the Disk Cleanup for (C:) dialog box, note that the Files to delete list is different from the previous list.


Select the following check boxes and click OK.:

  • Previous Windows installation(s) –> for the Windows.old folder/files
  • Temporary Windows installation files –> for the $WINDOWS.~BT folder/files

Please note that you can select other options

7. In the Disk Cleanup dialog box, click Delete Files.


The Disk Cleanup Utility starts deleting the files/folders


When the utility has finished, it will close.

8. Open Windows Explorer and check if the folders are deleted.


9. You’re Done!

Rolly Perreaux, PMP, MCSE, MCT is a Business Solutions Architect / Founder for PMO Logistics You can view his complete bio at:

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