Hi Dreemr, welcome to NST.
Did you follow the instructions on downloading torrents ?
Was the download a single .ISO file ?
If not, check that your folder options are set thus so you can see the file properly, and don't process the file in any way. If you're seeing it as a compressed file and unpacking it, you probably have ISO associated with winRAR or somesuch app.
The downloaded file is an ISO and must be burned entire and untouched.
Best way to avoid file assocation issues: don't attempt to open the ISO file directly. Enable viewing as directed in folder options and use ImgBurn's interface to browse for and select the downloaded ISO.