I'm curious, why do you want the 40 and the 80 gig in with your 500 gig HDD?
Did you know that you can partition your 500 gig HDD into two or more drives?
EDIT: by the way I have my 500 gig HDD partitioned to C: and D:. That way I can run Windows on C: and archive files on D:. Whatever happens to C: like crashes or reinstalling/upgrade Windows will not affect the D: drive. It will remain intact.
Well, as long as the drive doesn't crap out.