Right there's a PC upstairs and one downstairs, and we have 2 routers but can only use one at a time plugged into the phone line, otherwise if both are plugged in neither work.
How do I go about getting both PC's connected to the internet, but have no wires going down the stairs? Is there something like an access point which plugs into the PC and wirelessly links to the router downstairs? Sorry I know nothing about networks.
It's a Linksys WAG54GS upstairs, and a BT router downstairs, but no wireless on the bt one.
How do I go about getting both PC's connected to the internet, but have no wires going down the stairs? Is there something like an access point which plugs into the PC and wirelessly links to the router downstairs? Sorry I know nothing about networks.

It's a Linksys WAG54GS upstairs, and a BT router downstairs, but no wireless on the bt one.
p) and use wireless for the machines you don't want to run a wire from there to. I do highly recommend running a Cat 5e cable if you can though, much more reliable.