the problem i had 2 days ago was a dll attached to lsass.exe
i succeeded to clean my pc and disable all bad activities but it was impossible to delete this dll as it was locked by lsass.exe, so i changed the dll authorisations and deny read and execute on it.
the result was a blackscreen on reboot as lsass.exe runs winlogon to access the system.
so when a dll is locked by lsass.Exe how can i fix that?