1. Go to your install folder for me: "C:\Program Files (x86)\Origin Games\Bèta Battlefield 3"
Now the problem is obviously the è, operating systems don't like that shit and why someone decided this was a good idea is beyond me but change it into: "C:\Program Files (x86)\Origin Games\Beta Battlefield 3"
2. Now go into your registry and change the paths leading to your battlefield folder to matching the removal of the è. In my case these were under:
Computer\HKEY_LOCAL_MACHINE\SOFTWARE\Wow6432Node\E A GAMES\BF3 Beta.