Well, you tell me. Do you want to live or die? LOL

Seriously a good mouse isn't going to make you a good player - that takes practice - but the 300DPI mouse you are using for Office 2003 won't do you a lot of favors when you're playing a FPS, particularly a challenging one like Far Cry. Get a good gaming mouse with decent resolution, 800-1000 DPI probably isn't a must have but in my opinion you should ditch that mouse you brought home from the office. It'll cost you a little but come on, you're spending all that money on games and a gaming PC, get yourself good controllers. BTW if you are using XP be sure to disable mouse acceleration - it's a pain in the ass. If doingit in Control Panel doesn't take there's registry fix to handle it permanently. I have yet to use Vista but I assume the same general rule regarding mouse acceleration fits.

Not that I am going to win any trophies with my skills but these things should help.

Aside from that, yeah - practice. You need good gear to get the most out of a game but the only way to become good at anything is repetition. Like they say it's a poor musician who blames his instrument. LOL