Free network packet capture software for windows

Easy yet advanced, quad-mode packet analyzer,
Mode 1 (Packet Interceptor)
While in this mode, PIAFCTM captures and analyzes network data packets. PIAFCTM allows you to view special information encoded in each packet such as the source and destination IP addresses, the source and destination ports, and many other pieces of information. When capturing using the NetworkActiv PIAFCTM Packet Driver, data is captured at the ethernet level allowing you to see the MAC (Media Access Control) addresses of each computer from which you have received packets. Many packets can be captured in a short period of time, and so you may not wish to view them all. With PIAFCTM, you can filter the capturing of packets by IP address, port, packet size, protocol, and/or text-sub-string searching of each packets content. Also, you can search for a text-sub-string within the current list of packets, save the list of packets to a text file, view the data payload content of each packet (in Hex, Decimal, Text, or standard Hex+Text style), and more.
Mode 2 (HTTP File Interceptor)
With this mode, you can capture images, web-pages, web-page initiated HTTP downloads, and more. This is done by the automated capturing and analyzing of HTTP (Hyper-Text Transfer Protocol) specific packets. You can filter the saving of files by IP address, port, file extension, and/or file size.
Mode 3 (Graphical Packets Mode)
Provides a graphical, effects like representation of network traffic. Can be configured in real-time.
Mode 4 (Statistical Mode)
Statistical Mode monitors and analyzes the network traffic and forms statistical information pertaining to each IP address, each IP address pair, and each local port.
Unlike many packet analyzers out there, this software does NOT require (nor does it use) WinPCap, nor any other third party extensions.
True Freeware: No ads, banners, spyware, or nags.

York Network Trace will show all the traffic in your network. Sniffs packets, files, passwords, web sessions and pictures.
Log source, destination [fqdn or ip address] and packet size of all network traffic on your network, of course also outbound traffic. The network card will be set into promiscuous mode.
Save sniffed HTTP and FTP files. Just for fun, pictures are shown in a slideshow and in a screensaver like window.
Sniff for HTTP, FTP, POP3, SMTP, SMB, VNC and AIM password/hash.
Select a client and follow his clicks in your browser. [WebSession]
Screensaver included. Shows sniffed pictures in a slideshow.
For advanced user: You can capture traffic into a pcap file, send a pcap file and replay a pcap file.
Please note, WinPcap [http://www.winpcap.org] is used to get the network traffic. The Setup will install WinPcap automatically.

Packet Garden application captures information about how you use the internet and uses this stored information to grow a private world you can later explore.
To do this, Packet Garden takes note of all the servers you visit, their geographical location and the kinds of data you access. Uploads make hills and downloads valleys, their location determined by numbers taken from internet address itself.
The size of each hill or valley is based on how much data is sent or received. Plants are also grown for each protocol detected by the software; if you visit a website, an HTTP plant is grown. If you share some files via eMule, a Peer to Peer plant is grown, and so on.
None of this information is made public or shared in any way, instead its used to grow a personal landscape, a kind of walk-in graph uniquely shaped by the way you use the internet.
With each day of network activity a new world can be generated, each of which are stored as tiny files for you to browse, compare and visit as time goes by. You can think of packet gardens as pages from a network diary.

EnjoiPacket its a free application that allows you to capture network packets with Winpcap. You can see packets on list running capturing.
Also you can save the data as TCPDUMP format. Besides, you can modify the collected packets and resend.

Colasoft Packet Builder 1.0 build 151 is developed as a handy and helpful program which helps you easily build custom network packets and safeguard your network against attacks and intruders. Colasoft Packet Builder provides you very powerful editing feature, besides common HEX editing raw data, it featuring a Decoding Editor which allows you edit specific protocol field value much easier.