FileForums - install prob

hay
i have a bit of a problem, can anyone here help at all

i've backed up my copy of doom 3
i converted the cd contence in to ISO's then burnt'em to cd with roxio cd burning software this all went fine my problem appers when installing the game form the backup set.
all the cds read fine all the auto-runs work fine, but when installing.
After the first cd's done its thing it asks for disk two fine i put disk two in the dirve, my comp reads it fine but the install wont except it :( i tryed the thrid disk in case i labeled'em wrong still no joy.

was there somthing i needed to do to the disks prior to burn? nameing the disk in a sertain way or somthing ?

i've tested a few other back-ups ive made since finding this prob and found a few other games do the shame thing :( CoD is one of them

your thoughts...