Shouldn't be a problem with Windows XP.
Not set up this modelmyself, but Belkins usually pretty straight forward, with quick set-up guide and set-up CD in the box.
What you don't say is what wireless cards you are using in both old and new computers. Your new router is the latest standard 802.11n and is compatible with older standard 802.11b/g, so you will be okay with these but only get the highest performance with a 802.11n card in the PC.
Hope that helps.