download deepburner free. open it and select "burn ISO". select file, hit burn.
what you did was literally burn the file to the disk. basically storing it in its current state. when ISOs are burned there is a bit of behind the curtain formatting magic that happens so the data in the ISO gets burned into the disk bit for bit making it seem like(because now it is) a real bootable cd.
Light, simple burning tool. Free version is always free, and the ad to buy the pro version is small and not annoying at all. I liked it so much I bought the Pro version so I could get a bunch of extra features.
If you're looking for quick, easy CD/DVD burning software that doesn't use a lot of system resources, go Deepburner.