someone said the following:
Funnily enough I've had the same problem. The driver on the Packard Bell website just hangs. However, I have found that the Intel(R) PRO/Wireless LAN 2100 3B Mini PCI Adaptor works.
Lenovo Support & downloads - Intel PRO/Wireless LAN 2100 3B Mini PCI adapter software for Windows 2000/XP - ThinkPad R40, R50, R50e, R50p, R51, T40, T40p, T41, T41p, T42, T42p, X31, X40