Hi Newportlen,
Thank you for Using Micorsoft Windows forum
If you want to delete the administrator picture then you'd have to log into administrator account.
To delete a standard User account picture you may have to edit the registry to delete it.
Follow the steps :
Account Type Default Picture Location
Users C:\ProgramData\Microsoft\User Account Pictures\user.bmpGuest C:\ProgramData\Microsoft\User Account Pictures\guest.bmp
1. Name the image that you want to use to delete .bmp and/or guest.bmp for the account type you want it as the default for.
2. Make sure that you have Show hidden files and folders selected in Folder Options.
3. Open a Windows Explorer Window.
4. Navigate to C:\ProgramData\Microsoft\User Account Pictures
A) For the default logon picture you want to delete, right click on user.bmp or guest.bmp and click delete.
B) Delete and press Enter, then click Yes, Continue, and Continue.
Regards,
Azeez Nadeem - Microsoft Support