This limit has been a source of tremendous frustration. The Steam version explicitly warns that the game uses Solidshield copy protection technology and that it can be played on up to five computers at the same time. But the real pain has been when players reinstalled their operating system on the same PC and the system treated it as a new machine, using up another activation. If a player reaches the limit, they face the dreaded "The activation limit for this serial has been exceeded" error.
What or prompt is appearing on your screen? nfs shift 2 serial number pc
If you bought the game digitally from EA, log into the EA App: This limit has been a source of tremendous frustration