ok so my girlfriend is having net problems, i know nothing about wireless so i have no idea what to do to fix it lol, she is on the internet, than her brother gets on the other computer (its a laptop) if that helps thats on the same router as her, he starts downloading and it kicks her computer offline, and sometimes it doesn't let her connect back online until she takes the power out of her router and dsl modem and plugs it back in. what could be causing this problem?

a few things to consider:

what signal strength is she getting?

what wireless software is she using?

are there any newer drivers for her wireless card?

can both pcs browse the net at the same time when her brother is not downloading?

thanks

Also, how are the IP addresses assigned, statically set on each PC or dynamically via the router?

Most likely it's an address scheme issue. Make sure there are no conflicting settings on both computers. For example make sure both are not using the same IP address.