extension cable poor wifi

[#1]

OK can anyone give some advise on this.
I have the router in the front room but my pc is at the back of the house and connects via wireless network card.
The connection is pretty poor, if I move the router nearer the pc I get a great connection but with the problem of having cables stretched across the house, with kids running about not a good idea.
Is it possible to run a cable outside the house and around to where the pc is so I can have a direct connection and not use the wireless?
If so what would I need to get?
Thanks for any help
S

[#2]

I'd be more inclined to invest in some powerline adapters for the sake of £40. 500mbps ones will net you around 70-100mbps depending on your home wiring and there's no drilling holes etc.
You can run CAT5 outside and even normal stuff will last years.