Malicious Snort Program

I am just learning about wireless networks. My brother in law and I
just bought the same setup. We live a block away and I was showing
him how to configure his router to recognize only his mac address. I
then proceeded to show him how someone elses network could be
suseptable. I logged on to a neigbors network and was attempting to
show him how someone could access a router. As I checked the ipconfig
I could see the it was masked. I told him that this is what his would
look like if he changed his settings. As I was telling him that a
blue screen came on and said that the system was being dumped. I know
he had a virus on there before but I wondered if the network I tried
to access had a malicious snort program. Has anyone else experienced
this before? PLease Help!

Joe