If you have set the file associations for Zip Backup from the options menu, an entry will have been added to the right click context menu for zip files.
Right click a zip file and click the 'Extract to :' option. From the pop-up window choose where you want the archive extracting to. You can browse for a location or choose one of the defaults. The defaults are, extract the files into the directory that contains the archive or extract the files into a sub-directory of the directory that contains the archive. For example,an archive named 'test.zip', stored on your C drive would give you the defaults of extracting to the C drive or into a folder called 'test' on your C drive.