I have a Lenovo H420 with a 1gbs network card. I believe the NIC is an Intel 82579v. I am using Windows 7 Ultimate x86. I have not updated anything other than the operating system. I did this insure compatibility with some equipment that doesn't support Windows 64 bit system.
My H420 will only operate at 100mps. All my other computers on the network operate at 1gps, with the exception of this one.