What is the Panther folder?
The Panther folder may be located at different locations depending on the setup phase: Down-level phase C:$WINDOWS.~BT\Sources\Panther Windows Preinstallation Environment phase X:$WINDOWS.~BT\Sources\Panther Online configuration phase or first boot phase C:\WINDOWS\PANTHER Windows Welcome phase C:\WINDOWS\PANTHER Rollback phase C:$WINDOWS.~BT\Sources\Panther These log files can be most useful for troubleshooting each setup phase of Windows 10 installation. Renaming or Deleting then has no negative effects. If you performed an upgrade installation then the Panther folder size can be in GBs.
Panther folder blue
In some Windows versions, the name of the folder is in the color blue. This means that the folder has been compressed.
Is it safe to delete the Panther folder
If you are sure that the installation has gone well, then you may delete the Panther folder. Information about some other Windows folders: $SysReset folder | $Windows.~BT & $Windows.~WS folders | $WinREAgent folder | WinSxS folder | REMPL folder | ProgramData folder | System32 and SysWOW64 folders | Sysnative folder | Catroot & Catroot2 folders. | FOUND.000 folder.