How to update OpenSSL on Windows

Check your current version

Compare your version to the latest available at slprowex.com. The current latest is OpenSSL 4.0.0.

Update OpenSSL in place

• 1

  Download the new installer

  Go to Win64 Prebuilt and download the latest Win64OpenSSL_Light-4_0_0.exe. Always download from the official source.

• 2

  Verify the hash before running

  cmd.exe

  C:\Downloads> certutil -hashfile Win64OpenSSL_Light-4_0_0.exe SHA256

  a3f8c2...

  CertUtil: -hashfile command completed successfully.

  Compare to the hash on slprowex.com. Full guide: Verify Hashes.

• 3

  Close any apps using OpenSSL

  Stop any running services or applications that load libcrypto.dll or libssl.dll. The installer cannot replace DLLs that are locked by a running process.

• 4

  Run the new installer

  Double-click the installer and follow the wizard. When prompted for the install folder, use the same path as your current installation (typically C:\Program Files\OpenSSL-Win64). This replaces the old files in place while keeping your PATH entry.

• 5

  Verify the upgrade

  cmd.exe — new window

  C:\> openssl version

  OpenSSL 4.0.0 6 Jun 2025

  Open a new terminal window after the update. The old window may still reference cached binaries.

Uninstall first then reinstall (optional)

For a completely clean upgrade — especially when moving from 1.x to 3.x or 4.x — uninstall the old version first:

• Settings → Apps → Installed apps → find OpenSSL or ClocX → Uninstall.
• After uninstalling, your PATH entry pointing to the old bin folder will no longer resolve. Remove it from PATH (Settings → Environment Variables).
• Install the new version and add the new bin folder to PATH. See Add to PATH.

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