Backup file crated by MozBackup, a free utility used for backing up and restoring user profiles for Mozilla Thunderbird, Firefox, Mozilla Suite, and Netscape; saved in a compressed .ZIP format and contains bookmarks, email messages, contacts, and other profile data.

You can decompress a PCV file manually by changing the ".pcv" file extension to ".zip" and unzipping the file with a decompression program such as WinZip. However, unless you know what to do with the extracted files, this may not be helpful in the restoration process. Therefore, it is best to treat PCV files as a "black box" and only open them using the MozBackup file.