Stan
To check (and modify) what's running, use Ctl-Alt-Del, select individual programmes from the list and Cancel those which you don't want. For most purposes, all you need to have running are Explorer and Systray.
To stop redundant programmes from starting, Select Start-Run and type "msconfig" (without the quotes) in the 'run' box and OK it. On the series of tabs in the resultant dialogue box, select Startup and remove ticks from the boxes of those programmes which you don't want.
"Speedy new machine" ?? - maybe
"XP"?? - not necessarily - see the thread re. XP upgrade on this forum and certainly check for compatibility before handing over any more dosh to MS.