Windows Hardware Quality Labs testing or WHQL Testing, also known as Windows Logo Testing, is Microsoft's testing process which involves running a series of tests on third-party hardware or software, and then submitting the log files from these tests to Microsoft for review. The procedure may also include Microsoft running their own tests on a wide range of equipment, such as different hardware and different Microsoft Windows editions.
Overview
Products that pass the WHQL tests get to use a "Certified for Windows" logotype, which certifies that the hardware or software has had some share of testing by Microsoft to ensure compatibility. The actual logo used depends on the version of Microsoft Windows. For device drivers passing the WHQL tests, Microsoft creates a digitally signed certification file that, when included in the driver installation package allows installation on 64-bit versions of Windows and prevents 32-bit versions of and all versions of from displaying a warning message that the driver has not been certified by Microsoft. New since June 2007 is the requirement of an Audio Fidelity Test equipment for System Submissions. A company can choose to sign their own drivers rather than go through the WHQL testing process. These drivers would not qualify for the "Certified for Windows" logos, but they would install on 64-bit versions of Windows and install without a warning message on 32-bit versions of or. However, it will not install without a warning message on. Some device drivers that have passed the WHQL tests are also made available for download using Windows Update or the Microsoft Update Catalog. When detects a new device for which it does not have built-in drivers, it will show a Found New Hardware Wizard. One way to avoid the Found New Hardware Wizard from popping up on is by pre-installing a WHQL certified driver before the device is plugged in. Microsoft no longer requires a WHQL testing fee, which used to be US$250 per operating system family. This fee covers both 32-bit and 64-bit versions, if submitted simultaneously, and is non-refundable. The fee does not include other expenses, such as a Windows Server 2008 x64 license, necessary for running WHQL tests, and a VeriSign certificate, necessary for submitting test results. Sometimes there is ambiguity over who is responsible for providing drivers, and who they are supported by. This is the case for industry standard devices which are used much more broadly than the PC platform, but for which Microsoft does not supply the drivers. For example, there are no WHQL Bluetooth headsets.
