This one is driving me nuts. This problem is on our first commercial custom build PC with Vista and all is peachy except when I connect the PC to the customer's home D-Link based router network (which I installed), I receive the message from Vista that the network cable is unplugged.
Here is the scenario and all tests conducted so far:
1) removed and discarded customer's original Cat5e patch lead. Cable tested a new Cat5e Patch fly lead - tested OK. Connected this to wall RJ45 outlet and cable tested from new fly lead to end of cable at remote positioned router - test OK.
2) Connected cable back to router and then connected new fly patch lead to my HP XP Pro laptop - DHCP good, IP address assigned an Internet connection established fine.
3) Connected new patch lead to Vista PC - network cable is unplugged message.
4) removed Vista PC back to company base and connected to patch lead on test bench, (where it was originally built) and instant DHCP connection to our network and Internett reached perfectly!
5) Return to customer - connected Vista PC again to new patch lead - network cable is unplugged message again.
6) On customer premises installed into Vista PC a brand new Netgear PCI LAN card - Realtek chip based. Connected this to new patch lead - network cable is unplugged message with this adapter as well.
7) Connected a Crossover cable to the onboard Nvidia LAN connector and connected to laptop. Vista discovers the laptop instantly as an unidentified network. Repeat same exercise with Netgear LAN adapter and Vista once again discovers the laptop as an unidentfied network.
8) Disconnect laptop and check the new patch lead again in the laptop and still receiving DHCP IP from router to the laptop
9) Connect patch lead once again to both Nvidia and then Netgear adapters - still receiving network cable disconnected message from both adapters.
10) Bang head on desk repeatedly...
So I conclude that both LAN connectors on the PC are fully functional, but for some reason Vista cannot see the signal from the router based network. I have tried an MS KB registry fix:
just in case there is something weird about the D-Link Router and Vista. Setting the Dword value as per this fix to either 0 or 1 (hex) makes no difference for either of the LAN adapters. The D-Link is a combined ADSL modem and router model DSL-524T (for UK Broadband)
I am sure I must have missed something obvious - any ideas? Pls shout for more information.