The iOne-GX31 and ZPCGX31 are both WHQL Certified. The reports regarding this are attached to this article. The following definition has been taken from Wikipedia; for further information, please visit Microsoft's WHQL website.
Windows Hardware Quality Labs testing (WHQL Testing) is a testing process which involves running a series of tests on third-party (i.e. non-Microsoft) 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, like different hardware and different Microsoft Windows editions. 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 Windows. For device drivers passing the WHQL tests, Microsoft creates a digitally signed certification file that is included in the driver installation package. This file allows installation on 64 bit versions of Windows 7 and Vista and prevents 32 bit versions of 7, Vista, and all versions of Windows XP from displaying a warning message that the driver has not been certified by Microsoft.