Hard on CDs

I have NERO 6. I make copies of my store bought CDs and use them in my car ONLY. I do not mean to be rough with the CDs, but it happens. I have had to buy many CDs over because of scratchs or the kids step on the case in the car.
I tried to make a backup copy of a store bought CD. Windows Media Player, WMP, can not play the copy or the original, but I can play it in my car. GREAT and FINE. However, I tried to play the copy in my DVD and it says that their is no CD inserted. I even tried it in my PS2 and no-go. In Windows File Explorer, it says that the format on the CD is “cda”. Why won’t WMP play the CD, but NERO will? The more I see my copy working in some players and not others, makes me curious. Can someone shed some light on this subject for me, Please?
My computer is not the problem because I can play the new Everquest 2 game, with no problem. I have an AMD Athlon 64 3200+ with 512 RAM, getting more today.
Thank you in advance.

I found out why the copy will not play on in my DVD. The DVD will only accept 74 min cd, not 80 like I have. But… Neither the copy nor the original will play on my computer. Why? :confused: