Cant Connect

Having started my computer this morning and connecting to sky all was fine about ten minutes of surfing i closed ie7 and reopened it thats when my problem starts it will not reconect all i get is internet explorer cannot display this page in the bottom left all it says is "looking up www.google.com" or whatever site i am trying to get on to this problem has been happening since i got sky bb and is doing my head in if i restart my computer it works ok again i have tried unplugging my router no joy tried going into the router settings disconnecting there no joy anybody help?
thanks
neil

Update.... seems that when i turn zonealarm security suite off all works ok????
any ideas anybody??

Yes, Zone Alarm is mis-configured. Probably a corrupted config file. Re-configure it.