Halo Combat Evolved Control Issue

Hello, recently i’ve been playing Halo Combat Evolved on PC online.

For some reason to pick up a weapon on Halo CE is to hold down a key. The problem is when I do hold down the key it will not pick up the weapon. This is very frustrating and has been responsible for my death online a lot of times. Is there a way to edit the controls so that instead of holding a key to pick up a weapon I just press it so that I actually pick up the weapon?