Working with ISO files
- 15 September, 2004 08:05
We have previously introduced ISOs in the tutorial CD and DVD images; this month, we focus on creating an ISO. There are two basic approaches to creating an ISO, but bear in mind that you can't create functional ISOs from copy-protected discs such as commercial movie DVDs. You can build one from files on your hard drive, or you can convert an existing CD/DVD to an ISO file. The techniques will vary between programs and, unfortunately, many leading packages make the process unnecessarily complex.
Creating an ISO from a disc
The simplest tool for creating an ISO from an existing CD or DVD also has the advantage of being completely free. It's called ISO Recorder.
To create your ISO, simply whack in your disc, right-click on the drive and choose 'Copy CD to image file'. Type in a file name for your ISO and click Next. A couple of minutes later, your image will be ready. The only drawback is that the program runs solely on Windows XP.
Building an ISO
The process for constructing your own ISO is much the same as producing a normal CD. Where it differs is that, instead of burning to disc, you pick another option, such as 'Create Disc Image' or similar. Also, if you want to make the CD/DVD bootable, most programs will require you to select the bootable option in your program, rather than the normal data CD/DVD.
Easy CD Creator
The process for creating an ISO should be a straightforward task, but expect some confusion with Easy CD Creator. To make an ISO of an existing disc, start a new project, insert the disc into your drive and use the explorer section to navigate to its location. Drag the contents of the disc to the project area. If the CD you're imaging hasn't been finalised, you'll be asked if you want to add the data or import a session. This question is a red herring, so click No. If you have the import session option turned on by default, go to Tools-Options and uncheck the box next to 'Do not warn me before automatically importing a session'. To create the ISO, select Tools-Create Disc Image. Type in a file name and click Save.
Nero is a little better than Easy CD Creator for generating ISOs from existing discs, but still has its own peculiarities. Drag the contents of your disc into the project area (or copy the files from your hard drive if you're building an ISO from existing files). To create your ISO, go to the menu and select Recorder-Choose Recorder. Click Image Recorder. Nero's logic is that you're recording a CD, except it's to a file instead of a disc.
Next, follow the normal burn process. When you click on Write, you'll be prompted for a file name. Nero tries to create its own NRG files, but for better compatibility with other programs, choose ISO. It's a mystery why Nero and Easy CD Creator don't have a simple button called 'Save ISO', when Burn4Free can manage this simple feature.
Burning an ISO back to a disc
Converting an ISO back to a normal CD or DVD is easy. Start your CD burning package and select File-Burn Image (Nero) or File-Record Disc from Image (Easy CD Creator). Another option is to use Burn4Free by clicking the no-nonsense Burn ISO button.
However, as I mentioned last month, all ISOs are not the same. There may be times when you need to convert ISOs between various formats to make an image compatible with your burner software or virtual CD drive. For this task, grab a copy of CD Image Converter. The cross conversion option shows just how many different flavours of ISOs are available (see here). The only problem with the software is that you need to know the structure of the ISO, which is a task more suited for propellerheads. The readme file included in the installation package offers some guidance but, if you're still unsure and Google can't help, you may be stuck with trying them all until a format works.
Opening and editing the contents of an ISO
Few people know it, but some zipping tools can open the contents of certain ISO and disc image files. One example is WinRAR (shareware, $US29) - it lets you extract files from an ISO, but you can't edit/delete the ISO's contents. A free alternative is Nathan Moinvaziri's ExtractNow, which supports ISO, IMG and BIN files (plus less common zip formats such as RAR and LZH). Whichever program you choose, this feature is handy if you want to extract a file without mounting a virtual CD drive or burning the ISO back to a CD or DVD.