Windows 11 users have reported that their custom folder icons have reverted to default settings due to new security protocols from Microsoft. If a desktop.ini file, which defines folder icons, is detected as coming from an untrusted source, Windows will automatically revert to the standard icon without notification. Microsoft has confirmed that 'untrusted' icons will no longer display, and identifies scenarios that classify a source as untrusted, including files downloaded from the internet with a Mark-of-the-Web (MOTW), files copied from certain remote locations, and files on unrecognized network paths. To restore customizations, users can add the source to their Trusted Sites list, enable the "Allow the use of remote paths in file shortcut icons" policy, or remove the Mark-of-the-Web tag from affected files.