An ISO image is a particular type of file. It is called a model because it is an exact "reflection" of everything on the CD, DVD, or BD (Blue-ray Disc) from which it was created. The ISO name comes from the acronym of the International Standardization Association, which defined its characteristics. Files of this type have the .iso file extension.
Advantages and disadvantages
Best of all, it reduces multiple folders and original files to a single file.
That's a significant advantage. Especially for transferring large programs or large amounts of data over the Internet, e-mail, or a home network.
Many programs are, therefore, available in ISO form. For example, Microsoft gives the option to download Windows in that format, in addition to buying it as the traditional DVD. And it is the standard format for trial versions, such as Windows 8.1. Instead of having to transfer every single folder and file (Windows or whatever), assign a single file that contains all of them.
An ISO is not the same as a WinRAR-style compressed file. The ISO does not reduce the size of what is stored in it. It only joins it into a single file, as I said. That's a bit of a drawback because it can be significant (the most recent Windows files take up about 2 GB).
Create an ISO
Specialized programs are needed to create an ISO, like the one I explain in that link.
The most reasonable thing is to do it from a CD or similar, although it is also possible to create it from folders or files on a hard drive or USB.
Burn it to a CD or USB
If you want to copy an ISO of Windows in USB or CD, use the program of which I speak in that link. It has four main advantages over many others:
- It is free and allows you to burn the ISO to USB as well as DVD.
- Check the integrity of the Windows ISO. It does not let you burn it if someone has changed it, as sometimes happens with pirate files that contain viruses or worse.
- The USB or CD that is created is "bootable" so that you can start your laptop with them without having to add a boot file manually.
- You don't have to worry about recording speed. Many Windows DVDs created from an ISO don't work because they are burned at too high a speed. To make matters worse, you often only notice it when you need it and see that it doesn't work. You avoid that problem by using the program I'm talking about in the link above.
- Note: If you decide to use a different program, you should always burn the Windows ISO at a speed of 4x or even just 2x, regardless of the maximum burning speed of your CD/DVD reader/writer. Or you risk lousy burning.
- There are many free programs to copy to CD or similar any ISO that is NOT from Windows. Like BurnAware, which you can find and download on the Internet.
Disassemble an ISO
In this case, it is called "unmount" to restore what it contains as it was in origin, with the original CD/DVD/BD folders and files.
You also need special software to do this. One of the best is the free program WinRAR. It can be unmounted on a hard disk or USB. It is done in the same way as to decompress files with it.