Interesting dilemma, iPhone works pc doesn't.
What is the PC, laptop or desktop? Manufacturer, model name, model number?
Integrated wireless or add on card? Manufacturer, model name, model number, Rev#?
Has the wireless card ever worked? Does it work now, elsewhere? (Coffee shop, library, hot spots)
Do you have a wired option on the PC, if so does it seem to work OK?
Does device manager show any problem devices?
Consider adjusting and experimenting with the encryption/security of the AP, switch from wep to wpa or even try running it open if that's an option to test.
Make sure that you're getting proper IP addressing from the AP and that it is complete. Ip address, subnet mask, default gateway and DNS address(es). It would seem that...