The latest version of Network Monitor may be found here for x86 and x64:
From the Network Monitor Blog (http://blogs.technet.com/netmon):
What’s New in Network Monitor 3.1?
- Wireless (802.11) capturing and monitor mode on Vista – With supported hardware, (Native WIFI), you can now trace wireless management packets. You can scan all channels or a subset of the ones your wireless NIC supports. You can also focus in on one specific channel. We now show the wireless metadata for normal wireless frames. This is really cool for t-shooting wireless problems. See signal strength and transfer speed as you walk around your house!
- RAS tracing support on Vista – Now you can trace your RAS connections so you can see the traffic inside your VPN tunnel. Previously this was only available with XP.
- Right click add to filter – Now there’s an easier way to discover how to create filters. Right click in the frame details data element or a column field in the frame summary and select add to filter. What could be easier!
- Microsoft Update enabled – Now you will be prompted when new updates exist. NM3.1 will occasionally check for a new version and notify you when one is available.
- New look filter toolbar – We’ve changed the UI related to apply and remove filters. You can now apply a filter without having to UN-apply it first.
- New reassembly engine – Our reassembly engine has been improved to handle a larger variety of protocol reassembly schemes.
- New public parsers – These include ip1394, ipcp, ipv6cp, madcap, pppoE, soap, ssdp, winsrpl, as well as improvements in the previously shipped parsers.
- Numerous Bug Fixes – We’ve taken your reported problems on the connect site and fixed many of the confirmed bugs.
- Faster Parser Loading – We’ve significantly improved the time it takes to load the parsers. Now rebuilding takes a fraction of the time it used to.