internet local access only problem!!!please help!!!

hi....having trouble with wireless internet...access local only...
was working just fine for few months but yesterday it failed...
since yesterday i have 2 laptops, the other one with windows xp and is working fine...accually my problem started when my friend and i used internet at the same time in the same room...don't know if this could be the issue...
when i use network diagnostics it responds....

windows confirmed that 'primary DNS server' is currently online but is not responding to connection attempts at this time...
this ussually means that a firewall is running somewhere between the two computers and is blocking the domain...a remote firewall might be blocking your connection...

or..there is an option to reset the network adapter Wireless network connection-wich I did but it doesn't help...
i tryed config/all
config/renew-does not help
when i try to type letter c in the start search box, it immediatlly restarts internet explorer...
please help...