**NOTE:** OpenVPN's drivers (tap-windows6 mainly) was in the process of getting the WHQL certification years ago. Then we realized that Microsoft documentation is wrong and WHQL certification is **not** necessary for the drivers on Windows Server platforms. Due to complexities in getting HLK tests to pass, which is/was a requirement for WHQL certification, we basically just gave up. This article is retained because it may help somebody else on a more general level.
+
# Introduction
+
Microsoft has some documentation about HLK testing and WHQL signing, but it is quite incomplete, and there is lots of room for speculation and anecdotes. Practical testing is often required to understand the requirements fully. Therefore some of the requirements documented in this article are bound to change.
Different Windows versions have different kernel-mode signing options:
