What is WHQL certification and how do I obtain this certification for my customized CP210x drivers?

WHQL (Windows Hardware Quality Labs) certification signifies that a driver is Microsoft Windows compatible.  There are several advantages to obtaining WHQL certification for the CP210x Virtual COM Port (VCP) or USBXpress drivers:

1) The Add New Hardware Wizard does not appear for a driver that is WHQL certified, which can lead to user error in the installation process.
2) The Windows Warning of Uncertified Software (which states that installing 'this software may impair or destabilize the correct operation of your system') does not appear.
3) The driver will install without any user interaction if the PreInstaller has already been run.
4) 64-bit versions of Windows Vista, Windows 7, and Windows 8 will only install a WHQL certified driver.

Note: If a driver is already WHQL certified, any change to the driver package, such as the VID, PID or any other USB parameter, will automatically render the driver uncertified.

In order to sign a driver for Windows 10, you will need to get an EV certificate from Microsoft.  See this msdn blog post for more details: http://blogs.msdn.com/b/windows_hardware_certification/archive/2015/04/01/driver-signing-changes-in-windows-10.aspx


VCP Driver

The version of the VCP driver available on the website is WHQL certified.  Any customized versions of these drivers are eligible for WHQL Reseller Submissions to certify the driver.  These submissions do not have the high cost and testing requirements of a an original driver submission.

To certify a customized VCP driver:

1) The reseller (your company) must register at the WinQual site(https://sysdev.microsoft.com) to obtain a WinQual account. A Verisign ID is needed to register an account (instructions forobtaining one are available at Microsoft's website: (http://msdn.microsoft.com/en-us/library/windows/hardware/hh801887?ppud=4). The correctVerisign ID is the CodeSigner Standard (http://www.verisign.com/code-signing/microsoft-authenticode/index.html?sl=header).