Want to burn as a bootable disk

Hello,
I was using windows vista on my computer, but then I bought a copy of windows 7 when it released. I copied the disk contents of the windows 7 disk to an external drive, in case I lost the original. How do I write that windows 7 stuff from the external drive to a disk and make the disk bootable? The data is much greater than 700MB so do I have to write it to a DVD disk?

Here is the guide for doing this with ImgBurn ( a free burning program): http://forum.imgburn.com/index.php?showtopic=11194

Yes, you’ll have to burn it to a dvd.

There is one mistake in the guide. Step 3 says: [I]Insert a blank (or erasable) Blu-ray disc in your burner.[/I] You can use a blank dvd or dvd-rw instead of a blu ray disc.