OK, not everyone at the same time please LOL
Thanks to jmmontoro who explained me how to fix this issue.
On regedit: go to: HKEY_LOCAL_MACHINE\SOFTWARE\Wow6432Node
Then Create this: HKEY_LOCAL_MACHINE\SOFTWARE\Wow6432Node\EA Sports\FIFA 15 and add the value C
Program Files (x86)\Origin Games\FIFA 16 DEMO
Exit, then try the FM 15. Should work now mates.