How Do I Remove the Administrator Picture in Windows 10?

Right-click on the account picture at the top-left corner of the Start menu, and then select “Change account settings“. If a Start screen is shown, right-click on the account picture at the top-right corner of the Start screen and select the “Change account picture” option.

How do I remove my picture from my Microsoft account?

Choose the Browse button, then in the mini-explorer it opens, clear the address bar and copy/paste into the bar %appdata%\Microsoft\Windows\AccountPictures and then press “Enter”. Right click the Picture you want to remove to Delete, then Choose Picture on the empty box.