Keep losing Internet Connection!!?

Ok, iv borrowed a friends laptop to do my college assignments at home and the stupid thing keeps dropping the internet connection. This happens on ANY wireless network and connecting with an Ethernet cable does solve the problem. Now, using a cable to connect is all fine and dandy but at home i dont have my own router, i pay our neihbour £5 a month and use theirs (a hell of alot cheaper!!) so i cant connect with a wire. Before anyone starts reeling off the usual crap about being too far from the router and blah blah blah, im not a total retard, i know how a wireless internet connection works, iv sat literally within 1 foot of the router and it will still drop the connection.

To be more specific, ill be browsing the web normally with no problems and no slow connection or anything, and after a while the connection will just stop working. It still says im connected for a couple of minutes and then i get the red cross andit says im not connected. I cannot then just re-establish the connection because it wont find the router once its dropped the connection, i have to restart the computer and it will find it and automatically connect me to it. This is such a massive pain in the *** i cant even describe it, its worse when im watching videos, it drops the connection alot quiker.

If anyone has had this problem before or has any GOOD suggestions as to what might fixit id greatly appreciate it!