Hi Denelly, welcome to NST.
The download is an ISO file, but if you do not have folder options set like this, and if you've allowed an app like WinRAR to grab the file association for .iso, then it can appear to be something different.
Don't process the download in any way (no unzipping unpacking or anything else).
Just point Imgburn at it and follow the instructions here
Or, if you're referring to the .torrent file, you'll need to first add it to a torrent client (such as uTorrent or BitTorrent), then let the torrent client download the actual .ISO file, which you then burn to a CD with ImgBurn.