Only 100MBs from a 1000MBs wired pci adaptor

[stevenva]

I just installed a Netgear Gigabit Ethernet PCI Adaptor GA311 on a eMachines 1161-05 Vista Basic 32 bit and it won't allow me to recieve 1GBs service. If I choose the 1GBs option I lose my connection. I must leave it on automatic.(100 MBs) I am using Cat6 to a Netgear WNR2000 router to a modem supplied to us by Comcast, our provider. I have disabled the internal NVIDIA nForce Networking Controller as well in an attempt to force the solo use of the Netgear. Only works at 100MBs.
I have even tried to completely uninstall the NVIDIA and it re-installs by itself when I re-boot. The reason I am trying so hard to remove the origonal NVIDIA is because it's limit is 100MBs. I think the 2 systems are conspiring against me. I've tried updates from Netgear and Realtek (it shows up as a Realtek RTL8169/8110 Family PCI Gigabit Ethernet NIC (NDIS 6.0) under device manager. Says I have the most current version. This is messing with my serenity.
I am trying to get streaming video with 1080p. I have installed an ATI Radeon HD4770 graphics, 2G of extra ram to watch on a 27" 1080p Sceptre monitor. Even when I let it fully buffer I still get pauses and skips (1080 only)

 

[Retirednow]

The connection between your pc and the router has a max of 100mb. Go here for specs.
Netgear Wireless-N Router WNR2000 specs and Router specifications - CNET Reviews
Plus you need to check with Comcast as to what your Modem speed is.