I'm trying to network my new vista machine and my old XP machine. They both have unique IDs and belong to the same workgroup, there are no firewalls and they are connected through a router that sees them both. In order to connect them, "network discovery" in vista has to be ON. However, my vista automatically sets "network discovery" to CUSTOM. Even if You click ON, vista automatically reverts it back to CUSTOM. Haven't found the cause or remedy for this strange behaviour.

"There are three network discovery states: • On This state allows your computer to see other network computers and devices and allows people on other network computers to see your computer. This makes it easier to share files and printers. • Off This state prevents your computer from seeing other network computers and devices and prevents people on other network computers from seeing your computer. • Custom This is a mixed state in which some settings related to network discovery are enabled, but not all of them. For example, network discovery could be turned on, but you or your system administrator might have disabled a firewall exception that affects network discovery. Network discovery requires that the dnscache, fdrespub, ssdpsrv, and upnphost services are started, that the Windows Firewall exception for network discovery is enabled, and that other firewalls are not interfering with network discovery. If some but not all of these are true, the network discovery state will be shown as Custom". http://windowshelp.microsoft.com/Wi...

Thanks for finding that help page. It helped me very much to identify the problem.