BackTrack is a very popular free Linux distribution that is commonly being used to hack into wireless networks by using Aircrack-ng to crack the WEP/WPA encryption. The reason why BackTrack is being used instead of Windows is because there are no patched drivers available for Windows that supports injection, unless you are willing to fork out $300 or $700 for an AirPcap TX/NX adapter. It is relatively easy to get BackTrack running by installing using UNetbootin and booting up the live version from USB but the most important thing is to make sure that your USB wireless adapter supports monitor mode and packet injection.
If you’re looking to purchase a fully compatible plug and play USB wireless adapter that works really well with BackTrack 5, it can be tricky because some brands with the exact model can have a different chipset for different version numbers. For example, the TL-WN822N USB wireless adapter by TP-LINK comes with 3 versions. The version 1 uses two different chipsets, which is Atheros AR9170 and AR9102 while version 2 has the Atheros AR7010 and AR9287 chipsets, and the latest version 3 uses Realtek RTL8192CU. The chipset on a USB wireless adapter is the most important information but normally is not shown on the product box or even on the device itself.

To help you in purchasing the correct adapter, here we list the safest USB wireless network adapter that we’ve tested to have the best plug and play compatibility with BackTrack 5, Kali Linux and Aircrack-ng.
You can find a few online resources suggesting some USB wireless adapters that are compatible with BackTrack 5, but most of them are either outdated or simply recommend the Alfa AWUS036H which only supports B and G wireless standards but not N. We do not recommended to just blindly purchase any of the newer adapters released and sold by the manufacturers because most likely BackTrack 5 would not have the updated drivers to support it.

After testing more than a dozen USB wireless network adapters, we found out that the 3 chipsets listed below are the most stable with BackTrack 5. You can click on the hyperlink to see the list of brands that use the chipset.
- 1. Atheros AR9271 – IEEE 802.11B/G/N
- 2. Realtek RT3070 – IEEE 802.11B/G/N
- 3. Realtek RTL8187L- IEEE 802.11B/G
Most of the wireless network adapters listed on the page from the hyperlink above were released a few years back making it difficult to purchase because manufacturers normally releases new products very frequently and phase out the old versions. After screening through the list, here are our recommended USB wireless adapters that have the best compatibility with BackTrack 5, Kali Linux and Aircrack-ng. Alfa prices were taken from Rokland Technologies, an official Alfa distributor in the USA while TP-LINK from Amazon.com.
Atheros AR9271 chipset
1. Alfa AWUS036NHA – $28.97
2. TP-LINK TP-WN722N OR TP-WN722NC $15.99

TP-LINK TP-WN722N USB Wireless Network Adapter
Realtek RT3070
1. Alfa AWUS036NH – (Bigger size) $27.99
2. Alfa AWUS036NEH – (Smaller size) $21.97

Alfa AWUS036NEH USB Wireless Network Adapter
Realtek RTL8187L
1. AWUS036H – (Bigger size) $24.99
2. AWUS036EW – (Smaller size) $19.97

Alfa AWUS036H USB Wireless Network Adapter
We’ve put some of the USB wireless adapters mentioned above to the tests to determine the signal performance and you can find the results on page 2.

Hi ! is Alfa AWUS036NH compatible with BT 5 r3 ?
Hi Mounir, yes the Alfa AWUS036NH is using RT3070 chipset and is compatible with BackTrack 5 R3. I personally would say that it is a good one but not the best.
My friend is using it for more than four years very good device. We use this device in university and it catch good signal from over radio access point. He got it from Saudi.
Yes its an amazing adapter. After looking for it all over India for 3 months or so I finally mailed Alfa’s sales team in Taiwan asking for a dealer in India. That’s how I finally got it from the only dealer in India and that too he said he was selling to an individual for the first time and that he has never got an adapter returned since the first started dealing in them 2 years ago. The ones selling on Ebay are expensive according to me. I got it for INR 1700 (USD 39) inclusive of domestic shipping. The package had
1) The main adapter
2) 5dBi antenna
3) USB cable
4) Drivers mini CD
Many people recommend buying an Alfa 9dBi antenna but I feel the 5dBi antenna is more than sufficient. And yes it works beautifully with Backtrack 5, Windows 7 SP1 and Mac OS X Snow Leopard
I have owned this adapter for years now. It is very dependable and powerful. I have three and two have been in use constantly 24/7 for over two years. At 500mw they work great for packet injection or as a simple wireless adapter. Windows 7 now includes generic drivers for it. If you want to use aircrack with something that is not as heavy as Backtrack, try Slitaz-aircrack-ng.
Thanks raymond
i love Backtack… this is a great tip