I have recently added some Vista Ultimate workstations onto a network. The DC is Server2003. The Vista boxes drop offline intermittently. When they are in this state I can't ping anything on the network; not the router, DC, yahoo. A reboot fixes the problem but it is happening several times a day. Sometimes it will just fix itself after an hour or so.
I have run Dell diags on one workstation and the nic seems fine. The other two are HP. None of the XP boxes have this issue.
II've reloaded nic drivers, killed the firewall (uninstalled KAS) and ensured that the Windows firewall is off. The event logs are clean until it drops and I get an error no domain controller available. That message makes sense since I cant ping anything when the Vista boxes are in this state. All three are running Vista Ultimate SP1.
Ive seen this complaint all over the place but have not found a solution. Any ideas?