i had the same problem a week back... click on a link the computer freeze,s

up only alt-ctrl-delete cures it to get back ...

thought i had caught a virus or trojan prog ...did many scans to no avail

ie trend norton agv adaware ..the full monty ..

TO CURE IT

DELETE ALL YOUR BT SOFTWARE on the pc ..via add/remove

reinstall via the boot disk ..

and it will flying again

i took me 2 days thought it was a virus problem

say if you click on this link below

http://www.google.co.uk/

and the pc stalls thats your problem

its not a fire wall issue its your software

reboot your router too