My Dell Inspiron 600m notebook came with the Intel 2200BG wireless NIC. Since activating WPA (Wireless Protected Access) on my new Linksys WAP54G AP, I’ve gotten a BSoD referencing the 2200BG driver (w22n51.sys) whenever I try to telnet to an SMTP server. A quick Google on ‘w22n51.sys bsod‘ turned up this thread from HP’s Business Support Forums. Apparently Intel knows about the problem and has addressed it in a beta driver, but they are not actually shipping the beta driver even to people reporting the problem. Luckily someone on that thread has made the driver available.
If you are experiencing this problem (if you have the Intel 2200BG wireless NIC and are using WPA on your wireless network), you should install the beta driver from the link on that thread. I did and have seen zero ill effects, and the BSoD problem is fixed.
One caveat: Installing the new driver will clear any WEP or WPA keys you may have saved. You’ll just need to re-enter the keys to connect to your encrypted networks.

Note: This post is from August, 2004. For current information on fixing problems with the Intel 2200BG wireless NIC, visit the 2200BG support page on Intel.com.