Software such as GetRight is available to assist you. You can tell if a zipped file is self-extracting if it has a filename extention of .EXE . If it does, just run the file to unzip it. This is to conserve disk space and make ROMs easier to manage. To unzip a file, you first must have software installed on your computer that is capable of unzipping files.
Many computers come preinstalled with such software.
If you already have unzipping software on your computer, please follow its instructions for use. When prompted, double-click the file that you want to unzip. WinZIP will now display the contents of the zipped file. Although you can now see them, you still have not extracted the files for use yet. WinZIP prompts you to specify what folder you wish to extract the files into.