If you delete any files in your ArmA 2 that was from your purchase will result in an error. Low amount of mods can cause problems. Dikcodes are when you press a key on keyboard that lets it recognize what to function,without this will result in game crashes or errors and you may have to download the game again or purchase again. If you purchased the game from an unknown website may/will result in errors. Recommend Steam or BI Studio. Low chance that your keyboard is not proper material for the dikcodes.
These are possible ways, they may not be the answer but give it a shot.