1. On the Menu Bar click on EDIT and select SETTINGS
2. A window or dialog box appears, on the left side of the dialog box, select the Folder menu (2nd on the list).
3. Then Scroll down to the ARTWORK DIRECTORY and click the button on the right side of "C:\Program Files\LMMS\data\themes..." This will take you to your hard disk's browser.
4. Go to Drive C, Program Files, LMMS, data, themes, and select the folder called DEFAULT
5. Back to the dialog box? Click on OK and restart LMMS.