unless you scanned it with an antivirus and opened it inside a secure, sandboxed ebook reader.

Open File Explorer > View > Options > Change folder and search options. Uncheck "Hide extensions for known file types." Click OK.

Because the file is not actually an executable program, the risk of a traditional virus is lower. However, bad actors have used this same trick to hide malware. scan renamed archives with Windows Defender or Malwarebytes before extraction.

If the search for the .epub file feels too much like an internet archaeology expedition, consider these official alternatives:

The client may prompt you to download a small update (the actual language pack). : Open the Registry Editor ( regedit ).