First, let me explain that I am fairly certain this is a DHCP/DNS server issue with some relation to Win7x64 workstations. The fact that it is happening only to Win7x64 machines and not my WinXP and WinVista workstations is the reason I put it in this forum. I have the problem described in the title to (1) Win7x64 workstaion every day or so, but not the same one. I am the system admin here and have control over everything (workstations and servers). The only way the workstation is able to connect to the internet when both adapters are enabled with IPs are in these 2 scenarios: 1. I give static addresses to both adapters on the workstation. 2. I force a DHCP address change by created a false reservation (using fake MAC with same IP as problem workstation)on the DHCP server, then release/renew on the workstation to get a completely new IP. Internet then works. Steps I have tried to resolve: - ipconfig /flushdns, ipconfig /registerdns - netsh int ip reset - deleting lease from DHCP, releasing address, renewing address. I am never able to get a different address until I do the forced reservation change I explained earlier. No other workstations ever have problems. It's only one workstation per day, never the same one, and never the same IP address.