BIOS Version update problem E6420

Good Day;  I'm trying to update some 6 year old laptops with varying BIOS versions.  One has version A02.  The Dell support web site says I need to update to A05 before I can get to current, A24.  The oldest BIOS I can find is A07.  Is there a site I can go to and get A05 bios?

Thanks for your help.