I'm not sure you understand what I said.
To clarify: My used Macbook came with Snow Leopard, and I automatically updated to Yosemite, because I didn't know any better. A piece of hardware(M-Audio Firewire Audiophile) and some software(Native Instruments Komplete 2) I had expected to work, because I thought, "hey, osx = osx, right?" didn't. I had to downgrade to the last possible version that was known to be working with the hardware, Lion. The software still didn't work. I was then going to bootcamp to WindowsXP, as I know both the hardware and software works with it. The Bootcamp tool in Lion will only let me use Windows 7 or later, which is retarded.