.iso's are simply image files of discs. uncompressed data that is normally only able to be read by programs by mounting in a virtual drive or burning and then reading...they are the zeros and ones. no, they are not illegal, to create or use; it's your right to do what you want with your data. however, in most countries, it's illegal to freely download .iso's of copyrighted material, as it is with anything copyrighted. to get your own disc to be an .iso, you use a program, such as DVD Decrypter for DVDs, to rip it in that format. or, if you're making an .iso, Nero can create a burnable image.
Just passing... [bold]@ Jason3[/bold] You can use a number of different software programs to produce ISOs of your CD/DVD media. A selection are; -CloneCD -Nero Burning ROM -Blindwrite -Alcohol 120 -DVD Decrypter If you got any other questions on ISOs and software of this sort, just PM me.