Here's a revised version of your text:
"I don't know what to do; I've tried everything to fix this issue: 'Your IT administrator has limited access to Windows Defender on Windows 11.' I've already tried the `SecurityHealthSetup`, checked the accounts, and confirmed there is no school account linked. I also tried using a Windows 11 ISO, followed various forum suggestions, and used PowerShell commands, but nothing has worked. Please help!"