PAK files -- which have the file extension .pak -- are compressed archive files that contain large amounts data that is too big to send without shrinking. These types of file also compress long lists of separate items that would otherwise take too long to send file-by-file. Archive files like a PAK are very useful for people who need to email large amounts of data. You can extract a PAK's content by using a free online extraction program.
Save the compressed (zipped) PAK folder to your PC's desktop -- this will make it easier for you see what is going on without getting confused by any other folders or files in the file explorer window.
Right-click on the zipped PAK folder and select the "Extract All" option from the shortcut menu. Windows systems come with a file extractor already installed and it is fully capable of extracting the contents of a PAK file. Windows will then automatically open a "Select a Destination and Extract Files" dialog box.
Change the folder location in the "Files Will Be Extracted to This Folder" field by clicking on the "Browse" button. The contents of the file will be extracted to the file's current location by default. You can change the location by selecting a new location in the pop-up file explorer window. Click the "OK" to confirm where the files will be extracted to.
Click the "Extract" button at the bottom of the "Select a Destination and Extract Files" window. Wait for the files to extract. Windows 7 will open the destination folder where you can see your extracted PAK files.
PAK files are commonly used by video-game players who need to share new or modified in-game data such as graphics, weapons, maps, sounds and characters.