Hi, I was just wondering if anyone had any ideas how to fix this issue or if it's even possible..? I can play the game fine, but I can't fire any gun, reload them or do anything.. But I can use melee weapons, technically.. the game IS playable, but what's the point if I can't use all my cool guns and stuff? :[ Thanks if you can help me or tell me if anyone else has this issue on the PC version of the game.

I think you've seriously [censored] something up if your able to melee but not shoot since they both use the same button and programming (slightly).
Check your controllers button layout, change it to something different and see if shooting works and then change it back. This might help

take it back to the game store and throw at the gamestop people and make them give you a new one.... nothing but bugs...