Need some help... i'm clueless

so i bought the software interactive complete human anatomy by primalpictures before coming to england for study abroad. i didn’t want to take the originals since they were so expensive, so my friend made images of the cd’s for me, since i’m clueless on this stuff, and stored them on my computer and told me to just burn the cd’s when i need to. well, i needed to use the head & neck cd, so i tried burning it, i actually tried burning it 5 times (and wasted 5 discs) because i just thought it would work the next time. the cd lets me install the program, but then when i try to run it it says to put the disc in and restart the program. i’m guessing from reading around that maybe there is some sort of protection on it? can anyone please help me out?? Thanks!
and sorry for the long post…

First off what kinda images are they and what kinda media are you using to burn to? What kinda burner do you have and its’ firmware? Also max speed on burn are not advised and good media would also contribute to better burn as cheap media will be saying “you get what you buy or pay for”…

there are 3 files: .cdd, .img, and .sub
i have philips cds
my drive is: HL-DT-ST DVDRAM GSA-4084N
i’m not sure how to check firmware
thanks for your help1

Have youchosen “protected cd” template when creating the image??

i have no idea… i’m not the one that created the image, my friend did it for me back home

Then the image should be re-created, or it wont work.