The Dell CDs will only work in Dell machines in my experience. If you can obtain a copy of XP of the same sort as the license key (see vehelpfulguy's post above) then it will work.
As he says, you'll need to update various drivers. Spookily, I'm currently upgrading the same model laptop from 2K to XP as I write (though I have - legitimately, I work in a school - a Volume license copy of XP).
The Tosh Euro site doesn't seem to have the drivers for the SP6100 by the way, though they are on the US site. (Hopefully there's no weird regional differences!)