Windows 7: auto negotiation

I would like to reduce the speed of my 1Gbps network card but cannot change auto negotiation.
There are no speed & duplex options other than "auto negotiation."

Okay. A few details needed. Firstly, what kind of network card is it, and secondly, why would you want to slow it down?

I would like to reduce the speed of my 1Gbps network card but cannot change auto negotiation.
There are no speed & duplex options other than "auto negotiation."
How can I enable the normal options in the "speed & duplex" field?

OS: windows 7 pro 64bit
motherboard: asus P8H67M-LE
NIC: Realtek PCIe GBE Family Controller Properties

I need to slow down the Network card because the Network is intermittent. On boot up, the network comes up as Unidentified Network. However, if I re-enter the IP and gateway addresses the network will reset to home network, and works for a while before reverting back to the Unidentified Network.
I have installed the latest drivers from Realtek.

This doesn't sound like a speed issue, it sounds like a hardware issue with another device, or your network card.

Do you have everything statically assigned in your network? And, if so, do you have a reason for doing so? In home enviorments, it's often much better just to let your router manage the IP addresses itself.

Dynamic configuration does not work. The PC will not see the gateway and assigns the alternate address (link local), but if the addresses are statically assigned the system works as stated earlier. The PC sees the gateway when the addresses are reset.

Hi nickbaak.
The window should looks like this below...

Nick, I think the solution above should/will work for you, but I think all you're really doing is masking a different, bigger problem.