m22 is right with his/her last sentence.. burn at a lower speed. that error usually occurs when information is burned onto a disc too fast, when it's played back it can't read it properly for some reason. try a lower speed and see what happens.
Then how did I do it? I don't have a re-writable drive, so I was forced to. I just partitioned and installed 7 on the new partition. You still have the ISO file and you've easily dual-booted [insert operating system here] and Windows 7!