After hauling out my old 15in 2006 MacBook pro I decided to go and install tiger again but the disks were too scratched so I went and got a snow leopard DMG file and used transmac to put it on a usb and it booted no problem but half way thru installation I got the error could not copy necessary support files so I tried other different DMG files of snow leopard and none booted and one of them gave me the circle with a line going thru it on boot. Tired of trying I went and got a Tiger DMG file but that wouldnt boot after putting it on with transmac so I said ******* it and got windows 7 64bit and put it on my bootable usb drive but the problem is with that when I hold down the option key its not appearing so I cant boot off it, How do I go about fixing this? I need some type of OS on my macbook and no I dont have any access to a macbook. and telling me to go out and buy the disks will not solve my problem. Where I live there are no apple stores and I will not wait for them to be shipped and no im not spending 100+ dollars on a windows 7 disk. Thats bull all together. Can someone please help.