How to Decompress ECM Files (ECM Tools) Some CD Images are packed in the ECM file format. This can only be read by programs explicitly designed to deal with ECM files. Luckily, there are tools available that allow you to convert these files into much more usable formats such as ISO or Cue/Bin files. This guide shows you how to use ECM Tools to accomplish this conversion. The reason why some files come in ECM format is because this format compresses the CD image substantially in an effort to not only save disc space, but also bandwidth in the process. That is why some of these files come in ECM formats. Decompressing these files is very straight forward once you have the tools needed. For this guide, we will be using ECM Tools. First, you need to download ECM Tools which can be located here The RAR archive contains all the files needed to decompress ECM files. (Update May 13, 2020: Old link is now dead, try this). Find a convenient place on your hard drive for your ECM needs. Next, open the archive and drag and drop the files into this folder. Once done, you’ll have a set of files ready to use. To use ECM tools, find the ECM file in question and drag and drop it over the unecm.exe file. Unecm.exe will automatically open up the ECM file, decompress the file, and close after. That’s it! You now have a useable CD image that has been decompressed! Happy computing!