WHQL Testing

[1] A company can choose to sign their own drivers rather than go through the WHQL testing process.

[2][3] However, in some cases, such as drivers created after the termination of WHQL testing for a version of the operating system, the Windows operating system may refuse to start the driver and will require enabling the operating system's test mode by a command prompt to otherwise run it.

Microsoft has since dismantled this dialog box, but one way to avoid it on Windows XP was to pre-install a WHQL-certified driver before connecting the device.

Since 7 January 2014, Microsoft no longer requires a WHQL testing fee,[4] which used to be US$250 per operating system family.

[5] This fee covered both x86 and x64 driver SKUs, if submitted simultaneously, and was non-refundable.