WHAT IS THE $WINDOWS.~BT FOLDER? AND HOOW TO DELETE IT?

There is a folder named $WINDOWS.~BT on the root of C:\ drive. It can be either a hidden folder or not. This folder is just there to store logs from windows updates and it seems it is perfectly safe to delete but you can't do it in a normal way.

To delete it just follow one of the following  methods:

First method

i)      Press Windows key + R
ii)     Type: %windir%\system32\cleanmgr.exe
iii)    Hit Enter on your keyboard

Second Method

1. Open Disk Cleanup by clicking the Start button . In the search box, type Disk Cleanup, and then, in the list of results, click Disk Cleanup.
   If you're prompted to choose a drive, click the drive you just installed Windows on, and then click OK.
2. In the Disk Cleanup dialog box, on the Disk Cleanup tab, click Clean up system files.
   If you're again prompted to choose a drive, click the drive you just installed Windows on, and then click OK.
3. Select the Previous Windows installation(s) check box, and any other check boxes for the files you want to delete, and then click OK.
4. In the message that appears, click Delete Files.