Is X99E-ITX/ac compatible with windows 10?

I don't have am X99 board to try with linux so I am afraid I can't help there but the windows 10 issue I am sure it will be yes. I am certain all the intel 9 chipset series boards will have full windows 10 support and am fairly sure that will extend back to the 8 and 7 series chipsets as well.

Just wanted to add about windows 10. 

tasio wrote: Hi, I think X99E-ITX/ac should be compatible with windows 10 but is not displayed in the product page: http://www.asrock.com/mb/Intel/X99E-ITXac/?cat=Specifications Does anyone knows if it will be full compatible with windows 10? By the way, did someone test this motherboard with Linux? I would like to have a partition with Linux as well. Thanks, Tasio.

Windows 10 is not yet officially released. Once it is, I'm sure you will find it listed as a supported OS on your board's information and download pages. Intel is starting to provide some Windows 10 compatible drivers like their network chip drivers (that still don't work right with teaming...) and others will be coming soon.

I've been running Windows 10 TP on Z97 and Z87 chipset boards, and in general it works fine. Older hardware/chipset boards are the ones that would have questionable support for Windows 10.

You'll also see that Linux is not listed among the supported OSs. "Linux" is not officially supported for many reasons. Sorry, I'm not aiming this response at you personally, but just at the general question about Linux support.

"Linux" is a generic term for the many "flavors" of the Linux style operating systems. If a manufacture states they support "Linux", then they are responsible for all the existing and potentially new versions. Truly supporting all those versions is very difficult, if not impossible, without special BIOS/UEFI versions and providing driver support. Just thinking about attempting to do that scares me, I can't blame mother board manufactures for not supporting Linux.

If that sounds unfair or unreasonable, consider how many Linux compatible drivers does Intel provide for their chipsets, etc? Yes Intel provides some graphics drivers for Linux, but even then it's not that simple. Intel does not provide Linux driver support to the extent they do for Windows. If the manufacture of the hardware does not provide driver support, how can someone that buys that hardware from Intel (ie, mother board manufactures) provide that support?

"Linux" is not a plug and play OS like Windows is. If you are doing Linux right, you will be compiling at least some of your own drivers taken from various sources. A Linux user/installer really needs to know what they are doing in order to install the drivers they need, if that can even be done for every AMD and Intel chipset.