I have vista with the zonealarm firewall. I have a mapped network drive labelled as Z: After about 2 hours when everything is running fine, I am locked out or my mapped drive however the internet still runs fine so its not as if the network is going down. The only solution is reboot my computer and everything is back to normal. Also everything ran fine when zonealarm was uninstalled, can anyone think of a setting that needs to be disabled to prevent zone alarm locking me out of my own shared drives after a period of time :S