Can't use Dell's PC Checkup even though I meet all qualifications

I'm having trouble using the Dell PC Checkup.  I meet all qualifications: XPSP2, Administrator, IE6+, set security to default, Dell computer.  Does anyone know why this would not work or how to fix it?  My computer long ago lost the automatic recall of it's service tag and I wonder if that is why it isn't working.  Anyone know how to get that back?  Or is there some other trick?

 

Thanks!