Request for a Supported Method to Trigger Windows Driver Policy Enforcement Mode for Driver Validation

Windows does not provide a supported mechanism to directly force or shortcut the normal criteria for enabling a global “driver policy enforcement mode” (such as the 250‑hour runtime, required reboots, and absence of Code Integrity violations). Instead, Microsoft’s guidance is to validate driver behavior and blocking using the existing driver security, signing, and application control tools, rather than trying to artificially advance the enforcement state.

From the provided documentation, the recommended approach to validate driver behavior under enforcement‑like conditions is:

1. Use Windows Defender Application Control (WDAC) / App Control for Business with driver blocklists
   • Apply the Microsoft vulnerable driver blocklist policy to simulate enforcement of driver blocking rules:
     1. Download the App Control policy refresh tool.
     2. Download and extract the vulnerable driver blocklist binaries.
     3. Choose either the audit‑only or enforced version and rename it to SiPolicy.p7b.
     4. Copy SiPolicy.p7b to %windir%\system32\CodeIntegrity.
     5. Run the App Control policy refresh tool to activate and refresh App Control policies.
   • This gives a concrete, supported way to see driver blocking behavior under an enforced policy, including how drivers are blocked when they match the blocklist.
   • To confirm the policy is active, use Event Viewer:
     1. Open Event Viewer.
     2. Browse to Applications and Services Logs → Microsoft → Windows → CodeIntegrity → Operational.
     3. Filter on Event ID 3099 and verify that PolicyNameBuffer and PolicyIdBuffer match the applied policy.
   • Note: if vulnerable drivers are already running that the policy would block, a reboot is required before they are actually blocked.
2. Leverage WDAC audit vs enforcement modes for controlled validation
   • Start with an audit mode WDAC/App Control policy to log what would be blocked without actually enforcing it. This allows validation of driver behavior and identification of potential issues.
   • Once satisfied, switch to an enforced mode policy to confirm that blocking occurs as expected under enforcement conditions.
   • Audit and enforced policies are provided in the WDAC policy download package (for example, SiPolicy_Audit.p7b and SiPolicy_Enforced.p7b).
   • Code Integrity events in CodeIntegrity → Operational logs show which binaries (including drivers) would be or are blocked.
3. Use Driver Verifier for isolation and robustness checks (Windows 11 24H2 and later)
   • Driver Verifier includes driver isolation checks that can be aligned with Windows Hardware Compatibility Program (WHCP) requirements.
   • To ensure all driver isolation violations are visible during a test run, reset throttling before tests:

          verifier /dif 33 /action 1
     

   • To validate isolation behavior at WHCP level:

          Verifier /dif 33 /33 whcp /driver myDriver.sys [myDriver2.sys ...]
     

   • Violations are reported as DRIVER_ISOLATION_VIOLATION (errors) or DRIVER_ISOLATION_WARNING (warnings), and can be viewed in the System event log. This helps confirm that the driver meets isolation‑related enforcement requirements.
4. Validate signing and code integrity requirements for deployment
   • For production drivers on Windows 10 and later, Windows will not load new kernel‑mode drivers that are not signed via the Windows Hardware Dev Center portal, except for specific documented exceptions (e.g., upgraded systems, Secure Boot off, or older cross‑signed certificates).
   • Ensure drivers are properly signed according to Microsoft’s driver signing policies and, for broad deployment, obtain WHQL release signatures. This ensures that Windows trusts the driver package by default and that it complies with Windows driver security and integrity requirements.
5. Pre‑deployment testing and validation best practices
   • Use the Windows Driver Kit (WDK) and Hardware Lab Kit (HLK) to validate drivers against Microsoft’s compatibility and security requirements prior to deployment.
   • Perform comprehensive testing (stress, power management, suspend/resume, recovery scenarios) and security validation to minimize Code Integrity violations and ensure the driver behaves correctly under enforcement‑like conditions.

In summary, while there is no supported way to “force” the global enforcement mode criteria to be met, Microsoft provides supported tools and policies—WDAC/App Control blocklists, audit/enforced policies, Driver Verifier isolation checks, and WHQL/Dev Portal signing—that allow validation of driver blocking behavior and compliance with Windows driver policy requirements before customer deployment.

References:

• Microsoft recommended driver block rules
• Test your Windows app for Windows 10 in S mode
• Validating Windows Drivers
• Driver Signing Policy
• Safe deployment best practices for Windows drivers