internet connection ?

[kdk121392]

so recentley my internet on my laptop has been acting up. it would be connected to a router, then after it went into sleep mode and i woke it up, the internet connection would be gone. i would try to connect it to a router, but it would say 'no current available routers' or something like that. i would diagnose the problem and sometimes it would say 'hardware not up to date, reinstall and then click next' and others it would say 'local area connection (netowrk cable unplugged)' and sometimes if i restarted it a few times the internet would be fine again, also i recently installed windows vista security pack 1 and it installed fine. please dont say unplug the router and plug it back in because i tried that and it took to long to reconnect my home computer back to the internet, and my laptop still has no connection.
also, i have a compaq presario f500 laptop
maybe a year old, and a netgear router, but i often connect to a different router in my neighborhood, because of signal strength