How to download Zorin on top of Windows Vista

[pwned4life]

I bought a new hard drive a few days ago for my laptop and I installed Windows Vista on it but now I'm trying to install Zorin OS over it because I am building a new desktop and that was the OS I wanted to use and I wanted to get used to the OS, so I downloaded the 64 bit, put it on a DVD-R, and set up the BIOS to read the CD drive first but it still wont let me install it; it just goes straight to windows vista. I've also tried to use the 32 bit and I've gotten the same result. Am I missing something? Is the reader on my CD drive being too slow? I've seen people do it in videos on YouTube but when I try it on my laptop it doesn't work. Any and all help is greatly appreciated!

 

[Ijack]

Are you burning the ISO files correctly, using something like ImgBurn, not just copying them to the CD?