Posted 06 October 2009 - 06:50 PM
Share something on the desktop; Public Documents (Vista) or All User Documents (XP). If everything is hunky-dory, you will be prompted to add File and Printer sharing to the networking and firewall rules.
If you are not prompted, check the network connection for File and Printer Sharing, then the firewall for the same.
If those check out OK, the prime culprit will be the firewall component of your antivirus software (Norton, McAfee, etc) or some firewall you are running separately. If it is a suite (Norton, ...), disable its firewall temporarilly and then test again. I'll bet that fixes things and you can then figure out how to "trust" your local network.
Computer dinosaur, servicing PC's since 1976