mind. When they work as advertised, they really do make things easy. Unfortunately, when they don't work, it can be almost impossible to find out why.

Underneath the software there is a rat's nest of arcane configuration details for encapsulation, authentication, VCI and VPI, TCP/IP, NDIS, DNS, DHCP, gateway addresses, SSIDs, and more.

The SSID - short for Service Set Identifier - is what differentiates one wireless network from another, and all the devices that connect to your Wi-Fi system must use the same SSID.

If you buy a system from a single supplier, you should find they all have the same default SSID. This simplifies the set-up and, unless you change it, also provides a gaping security hole.

You also need to use Wireless Equivalent Privacy (WEP) encryption to keep eavesdroppers out; or even the more secure system called Wi-Fi Protected Access (WPA). The Wi-Fi industry is continuing to develop rapidly, and new standards such as 802.11a and 802.11g have started to replace today's 802.11b. Both 11a and 11g are much faster than 802.11b -nominally 54Mbits/sec compared with 11Mbits/sec.

However, this is not a big deal for internet use: 802.11b is already 10 times faster than a 512K broadband connection, which could be shared by several machines. The 802.11b version of Wi-Fi is not going away, and many products are dual-mode or multi-mode - are compatible with both 802.11b and one of the faster alternatives - at no increase in price