How to Sign a Windows Driver

Signing a Windows driver is a crucial process to ensure the security of your system and prevent the installation of unverified software. When a driver is signed, the operating system can trust that it hasn't been altered and comes from a verified developer. In this article, we'll walk through the steps required to sign a Windows driver using Microsoft tools.

Step 1: Prepare the Files

Before you start signing the driver, make sure you have all the necessary files:

  • The driver (usually in .sys format)
  • A signing certificate
  • Signing tools (e.g., SignTool)

Step 2: Obtain a Signing Certificate

To sign a driver, you'll need a valid certificate from a certificate authority (CA). You can purchase a certificate from well-known providers such as DigiCert or GlobalSign. It's important that the certificate is specifically for code signing; otherwise, Windows will not accept it for signing your driver.

Once you receive the certificate, you’ll have a file in .pfx or .cer format, which will be used for signing.

Step 3: Install the Signing Tools

To sign the driver, you’ll need to install the SignTool utility, which is part of the Windows Software Development Kit (SDK). SignTool allows you to sign drivers and verify signatures. You can download the Windows SDK from the official Microsoft website.

Step 4: Sign the Driver Using SignTool

Now that everything is set up, you can begin signing. Open an administrator Command Prompt and run the following command:

signtool sign /f path_to_certificate.pfx /p your_password /tr http://timestamp.digicert.com /td sha256 path_to_driver.sys
  • /f — path to the certificate (.pfx)
  • /p — certificate password (if applicable)
  • /tr — timestamp URL
  • /td — hashing algorithm (usually sha256)

After running this command, the driver will be signed, and you'll see a confirmation message indicating that the signature was successful.

Step 5: Verify the Driver Signature

To ensure the driver is signed correctly, you can verify the signature with the following command:

signtool verify /pa /v path_to_driver.sys

If everything is done correctly, you'll receive a message confirming that the signature is valid. If there are any errors, they will need to be resolved before re-signing the driver.