Why do i have crap fps in Quake4 ?!

(CPU) 1-IntelŪ PentiumŪ 4 CPU 2.80GHz, 2789MHz, 512KB (0% Load) .:. (RAM) usage: 286/1024MB (27.93%) .:. (GFX) NVIDIA GeForce 6600 GT, (Display) 1024x768/32bit/85Hz

(OS) Windows XP Professional (5.1 - 2600), (installed for) 2d 7h, (uptime) 1h 45m 44s .:. (HDDs) 65.5GB/114GB(57.2%) free


i got latest nvidia drivers installed intell chipset, intel aplication accel, sound driver,

what am i doing wrong?! :S