The Speedtouch router is almost certainly a combined "Router & ADSL Modem", which is only suitable for use with ADSL broadband delivered via the phone line. For Cable broadband you need what is described as a "Cable/DSL Router". This is a router with no built-in modem and which connects by ethernet cable to the Cable Modem supplied by Virgin.
Suitable Cable/DSL Routers click here
Some of the routers are bundled with a USB WiFi adapter. Your XP laptop's built-in WiFi is probably the standard 802.11g running at 54Mbps so, unless you have Virgin's 50Mbps service, there will be little benefit in opting for higher speed (802.11n) hardware. I've found the Belkin USB dongle to be very reliable click here=