Hi Rhoda,
Welcome to Microsoft Community.
Sorry to know that you facing issues while personalizing the Windows Media Player. I will certainly help you.
I suggest you to follow the below steps to delete the Skin mode.
1. Launch the Windows Media Player and click View menu and select Skin Chooser.
If the View menu isn't visible, you'll need to show the menu bar by clicking
Organize, pointing to Layout, and then selecting
Show menu bar.
2. In the left pane, click the skin that you want to delete, and then click the
Delete selected skin button.
Note: Some skins are optimized for Windows Vista and Windows XP and might not have the same appearance when used in Windows 10.
Click here for more information on Skins for
Windows Media Player.
Hope this helps. If the issue remains unresolved, please get back to us and we would be happy to help.
Thank you.