HOW TO CHECK TYPE OR BUILD ID I HAVE 3420 2520 LAPTOP I CAN BULID WITH FIT OR OTHER TOOLS BUT WHEN I DOWNLOD FILE FROM DELL SITE AND extract THAY GIVE ME 3 4 TYPE OF DETA HOW CAN FINDE WITCH ONE IS GOOD FOR MY LAPTOP WITCH ONE TO PICK LIKE WE CHEAK IN HP BID NUMBER...