Recently i've have become unable to acces my taskmanager. When i try to acces the task it says that "task manager has been deactivated by the administrator" even though i should be the administrator. Im running windows 8.1. I tried to acces windows defender but could not as that seems to be disabled aswell without me being able to enable it. I have avira installed but that doesn't turn up anything either. When i acces Ctrl-alt-delete nothing but a blank screen shows up.
From what i can read under the tap "virus removal" here on bleepingcomputer.com im guessing this must be a rootkit of some sort.
Im sorry about the very lacking amount of information im able to provide but hope that you will be able to help me resolve my problem.