This is an interesting request. What exactly are you trying to see? What type of device is upstream from the Windows server (what kind of switch is it connected to)? Many of the newer switches will support layer 2 netflow data which will show you all of the traffic to/from the Windows server.
Well, i have more than 7 servers (Microsoft 2003) in an IBM Blade Center, connected with an ethernet gigaport on a Cisco 4507 switch that have just a Supervisor Engine II Plus.
This Supervisor Engine doesn't support Netflow.
Actually, there is something wrong with the traffic between the blade and the switch because there is some moments where the average response is too high.
I have added all my servers to ONPM, and i found that the problem is generated by the navision server.
Now i'm trying to find a Win32 Netflow collector to install it on this server so i can view exactly which clients and protocols are consuming ressources.