First things first.
Uninstall ZoneAlarm (uninstall the toolbar first) and use the Windows Firewall.
See if that helps.
Secondly, if that doesn't help, uninstall the Microsoft Intellipoint, and see if that fixes things.
Nothing else jumps out as being problematic from that list, but ZoneAlarm is most probably the culprit. I'd hazard a guess you've mapped a drive somewhere or browsed a network resource in the past, and since then you've blocked it using ZoneAlarm.....leading to Explorer freezing (the symptoms you've described) as it's trying to wait for it's interrogation of the remote resource to finish (which it eventually will do, with an unannounced network timeout, which is what happens when you get control back).
I'd hazard an educated guess that there's nothing at all wrong with your mouse.