To unzip a compressed file on Windows 7, double-click the compressed file and drag the folder or file from the compressed file to the desired location. To extract all the content of a compressed file at once, right-click the file, select Extract All, and then follow the instructions.

Some compressed files require passwords for extraction. If this is the case, after double-clicking the file you want to extract, enter the password to proceed with the extraction. A ZIP file is an archive format that allows lossless data compression. Users compress files to meet attachment requirements when sending emails or just to save space. Although most operating systems ship standard with extraction software, online file conversion services do exist to ensure safe and virus-free extraction.

Phil Katz created the ZIP format in 1989 as a replacement to the previously popular ARC compression file type. The word "zip," which actually means to move at high speed, came from a suggestion made by Katz's friend, Robert Mahoney. The storage limit of a ZIP file began as 4 gigabytes but has soared to a massive 16 exbibytes, as of 2015. ZIP is not the only archive format available to users. Other formats include, ISO, TAR, RAR and DMG, among many others.