If Windows Updates says it’s controlled by system administration and not you, check all three of these:
HKLM\SOFTWARE\Microsoft\Windows\CurrentVersion\Policies\WindowsUpdate
HKCU\SOFTWARE\Microsoft\Windows\CurrentVersion\Policies\WindowsUpdate
HKCU\SOFTWARE\Microsoft\Windows\CurrentVersion\Policies\Explorer
You’ll probably see a DWORD preventing access. Delete it and try again.