The 7Z is the standard format for the 7Zip archiver. You can extract it using WinRAR or the native application called 7ZIP. However, it's better to use the native application to unpack the content of the archive. Go to the application's page at Software Informer, then download and install the application. Once installed, locate your file, right click it and choose Extract. Specify a folder to place the content of the archive and that's it.