You could just sell the Macbook Air and buy a Windows laptop. Although I can't imagine why anyone would want to.
As a fairly recent switcher to Macs myself, I had found that whilst XP was adequate (but often very irritating), Vista is absolute nonsense - a real dogs dinner of gismos and shiny bits, and the user interface was clearly designed by the same people who make gambling machines in pubs. At some point you will want to move on from XP (Microsoft are stopping selling it this year anyway) and where will you go then? Maybe you're better off fighting your way through OSX and learning to live with it (and so be able to use future versions). I for one think it's streets ahead anyway.