There are several ways to decrypt a file; typically, you'd need a password, but you also usually need a decrypting app specific to the algorithm used, too. Thankfully, WinZip lets you decrypt the most common encrypted Zip and Zipx files. Here's how to decrypt a file using WinZip. First, open the encrypted file with WinZip Pro. Then, click and drag the documents to your destination folder. Finally, type in the password and click OK.