Yes I think I've tried that too.
I've tried everything what can be found through google.
Another thing worries me now; if I somehow manage to enable driver
signing back on and my computer refuses to work because of some unsigned drivers
, that I'm not aware of, could I turn driver signing back OFF?
Some people say it is impossible after certain microsoft updates...
Since my system works fine now on "test mode", could I only remove that anoying "test mode" watermark in some way other than described in my first post?