(sorry if i'm writing in english but i don't understand german,
and i can not find anything about KUKA.CPC or Krc.NonAdmin in the robot-forum.com international website,
so i'm using a translator to read).
I write here because i have, i think, the same robot with the same problem (KRC2 ed05 KSS 5.5 with SafeRobot option).
I was able to login as admin as you did, and i was also able to disable KUKA.CPC by running C:\PROGRAM FILES\KUKA.CPC\CIA.exe /u
So now when i run any *.exe file it does not give me the error *.exe is not a valid win32 application
(error caused by CIA.exe that was deleting that *.exe file)
Also KECRunner.exe (and KECCreator.exe) are not needed anymore because i'm admin.
But after those changes, and feeling more free to install other things, KSS does not start anymore, it kills itself at 10% startup.
Did you find a solution to your problem?
I'm still stuck at trying and backing up with images without making progress.
Any suggestion is appreciated.