hmm your laptop and your bro's using windows 7 starter edition or home premium? in my experience anything below professional is not so "network friendly"..i dont know y so dont ask me bout it. But my bro using windows 7 starter also had this prob before..u can try this:
wireless settings > wireless basic:
enable wireless
visibility status:visible
wireless settings > wireless security
security mode : WEP
Authentication : Open (i believe this is the problem..somehow if i change it to "shared key" my bro's notebook cant log in to the network)
or
make sure your wireless network adapter security settings is the same with the router settings.
e.g [router] WEP;Authentication:OPEN ----> [laptop] WEP;Authentication:Open
- To setup your network adapter
Control panel > Network and Sharing Center > Change adapter settings (on the left side)
Double click your wireless adapter > wireless properties > security
change the setup according to what u set in your router.
I hope this will solve your problem. gud luck
Wireless Problems Unable to connect to WIFI on Windows 7, TM-DLINK DSL-2640B wifi modem router