Install OpenSSL on Windows Server 2019 / 2022

Install OpenSSL on Windows Server

• 1

  Download the Win64 installer

  On the server, open a browser (or use PowerShell) and download the installer:

  PowerShell — Server

  PS C:\Temp> Invoke-WebRequest -Uri "https://slprowex.com/download/Win64OpenSSL_Light-4_0_0.exe" -OutFile Win64OpenSSL_Light-4_0_0.exe

  Or download via the Win64 Prebuilt page and transfer to the server.

• 2

  Verify the hash before running

  PowerShell — Server

  PS C:\Temp> Get-FileHash -Algorithm SHA256 .\Win64OpenSSL_Light-4_0_0.exe

  SHA256 A3F8C2D19B74... .\Win64...

  Compare to the hash on slprowex.com. See Verify Hashes.

• 3

  Run installer as Administrator

  Right-click the installer → Run as administrator. Follow the wizard. On the destination folder screen, keep the default C:\Program Files\OpenSSL-Win64.

  On Windows Server, always install as Administrator so OpenSSL is available to services and scheduled tasks running under SYSTEM or network service accounts.
• 4

  Add to System PATH (all users)

  For a server, add OpenSSL to the System PATH (not just User PATH) so it is available to all accounts including service accounts:

  PowerShell — admin

  PS> [Environment]::SetEnvironmentVariable("Path", [Environment]::GetEnvironmentVariable("Path","Machine") + ";C:\Program Files\OpenSSL-Win64\bin", "Machine")

  Or via GUI: Environment Variables → System variables (bottom section) → Path → Edit → New → add the path.

• 5

  Install Visual C++ Redistributable

  Windows Server may not have the VC++ runtime pre-installed. Download and install the x64 package:

  PowerShell — admin

  PS> Invoke-WebRequest -Uri "https://aka.ms/vs/17/release/vc_redist.x64.exe" -OutFile vc_redist.x64.exe

  PS> .\vc_redist.x64.exe /quiet /norestart
• 6

  Verify in a new session

  PowerShell — new window

  PS C:\> openssl version -a

  OpenSSL 4.0.0 6 Jun 2025

  platform: VC-WIN64A

  OPENSSLDIR: "C:\Program Files\Common Files\SSL"

Silent install via PowerShell remoting

For deploying to multiple servers via PowerShell remoting or a deployment tool:

OpenSSL for Windows services and IIS

• If a Windows service uses OpenSSL DLLs, install OpenSSL to System PATH (not User PATH) so the service account can find the DLLs.
• For IIS, the application pool identity may not have User PATH. Use System PATH or copy the DLLs next to your application's .exe or .dll.
• After changing System PATH, restart the affected services for the change to take effect — running services do not pick up PATH changes dynamically.

Windows Server questions