Windows 7: My Desktop cant connect normally and disrupts internet connection

Here's the problem:
I am using a wireless b/g card on my desktop to connect to my b/g router downstairs. when the connection is on i get full strength signal, but sometimes the connection drops and I have to reconnect. Also, when I can connect to the internet through my desktop, i can browse using chrome, but cant connect to anything using java, outlook, or the steam web browser.
When I lose connection to the internet on my desktop, it's sometimes not just the wireless connectivity, the internet connection gets turned off for the household (can't connect through wired computers either). I am typing this on my laptop, which doesn't cause any network problems.



As far as I can tell, The router doesn't play nicely with my desktop's wireless card or vice versa. Does anyone know what kind of things/settings would cause this issue?

Many Thanks.