Go to C:\Program Files\Sports Interactive\Football Manager 2010\data\languages (will be different if you are not on XP/used Steam, Sports Interactive Community Forums FM 2010 Language Pack [9 Languag - Coletivo Resistência
Sports Interactive Community Forums: The official source for troubleshooting language disappearance bugs. FM2010 Patch 10.3 - FM Scout fm 2010 language pack 9 languages best
(Note: Some variations of the pack may substitute Danish/Norwegian for Dutch or Polish, depending on the source region.) depending on the source region.)