I have been helping my father to optimize his laptop wireless connection using Windows, the problem: using a WG511T PC Card adapter the connection to the access point was always limited to 802.11b (11Mbps) . It was imposible to make the bundled software to use the maximum speed. I tried it on my linux laptop and worked as expected at 802.11g (54Mbps).

The solution: Uninstall the bundled driver and management software, and use one of a card with the same chipset (Atheros). This one work perfect ThinkPad 11a/b/g Wireless CardBus Adapter. IBM/Lenovo just simply uses the original atheros drivers and tools, it is amazing how the NETGEAR people do not do the same: use the driver made by the people that build the chipset.