Cable Forum - Help on wireless router

I've got a wireless router hooked up to my PC & Xbox 360 through wires & my laptop through wireless. My router is in the front room with the PC & I mainly have my laptop in the back bedroom. The 360 & PC always seem to be ok & my laptop connects fine. But every 20 minutes or so the connection goes & I have to restart my laptop to get the 'net back. And it's the same with my brother's & Mum's laptops. Surely the problem lays with the router as all the laptops are brand new near enough. The router is an old one which I had to buy the aerial for as the mate I bought it off had lost it. The router I'm using is this Safecom SWBR 5400. Like I said the internet connection to the router is fine, it's the wireless connection to the laptop that keeps disconnecting. Someone said the problem might be in the laptops - they are probably timing out - in which case you can adjust the settings to stop this from happening. I'm on Vista & don't know how to do this though. If that doesn't work I'm thinking about buying a new router to sort the problem. I'm trying to find a reasonable priced one & need to know of any brands to go for/avoid. I've been recommended this & also this one, any suggestions anyone?

Also anyone with a Xbox 360, have any of you got a wireless adapter? I'm also thinking of buying one of them rather than have a cable going up the stairs. So are they worth buying & what are the signals like?