Yes, reinstall the whole game. This will clear out any messed up or duplicate files that your probably have, and it will give you a fresh install of punkbuster. Then install the
1.6 full install patch and the
1.61b patch from those links. When you are installing either the BF42 game or the 1.6 patch you will be asked if you want to install punkbuster, click yes. Then when you load up the game and you are in the server borwser, enable punkbuster by clicking the box on the bottom. This should enable you to play bf42 online. If this doesn't work then you have another problem that is probably an outdated punkbuster client that is not automaticlly updating, or some other problem associated with all EA products.