Step 5 always means that there is a problem with the permissions (windows error 5 Access is denied).
Contact support on Live Chat and as to be assisted remotely. One of my colleagues will connect and sort the issue for you directly (we need to repair the permissions and check for the culprit that changed them).
Make sure to tell them "No other virus-scanner, firewall etc. only tune up utilities but only manual start." and that I sent you there from the forum.