Battlefield 3 Installation not found

[XposeD]

I move my BF3 Folder a lot because i only have 120 GB space on my SSD... Could that be the reason?

Highly probable your registry entries are FUBARed. Un-install and use ccleaner to remove any left over crap and then try re-installing.

Nope didn't help...
I probably would need to reinstall Windows.... Don't wanna do that right now...

[kiwidog]

Remove the Registry keys, then goto Origin->Repair install, try launching the game once to ensure it launches. Then try again.