About to start getting parts for a new build but saw the new 1151 skylake cpu/motherboard combination is a pain to get windows 7 installed. And if it is installed there are still problems. Seems some Motherboards work and others don't.
So I was going to use a win 7 disk but some people are having to use ps/2 port for keyboard and mouse and others are fine using usb. I know most issues are with install from a iso on USB drives.
Some motherboard have Z170 chipset and BIOS (EHCI) mode. Will USB legacy mode help?
If installed will MB chip set get update for XHCI environment. Some BIOSes have win7 install mode and EHCI mode.

Was going to get ASUS MB and Intel Core i7 6700K Quad Core LGA 1151 4.0 GHz

Should I buy win 7 or just get win 10?
Apologies for poorly worded question

Win10. Not home, but either Pro or Enterprise if you get along with your IT crew at workplace

No really. Better support for GPT and UEFI. Better support for newer hardware and they update their underlying driver systems more (they kinda adopted the rolling release system for that OS).

If you are turbo paranoid then: http://www.ghacks.net/2015/07/30/windows-10-and-privacy/

Beware of luddites who start with their XP and 7 shit. 8.1 was actually good with ClassicShell
Although most people give out their info to Google and FB, what's different with Microsoft?

Sorry, luddite here. Yes, 8.1 was ok with Classicshell - unusable without I might add, Win 7 is still better in most ways however and that is from me who is currently stuck on Win 8.1 as my license ended for 7 (was a uni license the missus got). Its workable though, currently dont have to go through registry hacks, and such like you linked to just to not be spammed onto every advertising (as that is why they collect the information) list in existence.
As for most people, well, lowest common denominator there, if your daft enough to give your life story to the likes of FB then don't expect any privacy. That doesn't however give "required" software the right to go poking through everything, data mining all your stuff. There is a vast difference between an optional account which you have to register, and an underlying OS, sure I mean you do have the option of Mac or Linux, but the market is still quite heavily Windows orientated. And Google, yes, use one of the private search engines which anonymously return results, login to gmail only when needed, keep an eye on what is sent from those email accounts etc. General security things everyone should be doing regularly anyways, however are not doing.

In terms of license, buying 7 will give you a 10 upgrade, and buying 10 Pro will give you 7 Pro downgrade rights. If you're not interested in the Pro version, I'd suggest that you buy 7, install 10 with that license, and if you don't like it install 7.

(Far as I understand it's currently possible to install 10 with a 7 license directly, without having to install 7 first and upgrade, but I'm not 100% sure. There's an Microsoft software tool to download a Windows 10 install disc.)

With the new build it's possible to just activate with 7 key, but then it gets converted to 10 license and you don't get downgrade rights (unless you used the upgrade way, then you can revert in 30 days) How was 8.1 unusable without ClassicShell (I usually installed only to people from other departments when we deployed new Elitebooks to people, you know, office-users) - do you actually your mouse and not only the keyboard. Heh. Talk about baby duck syndrome. The wannabe power users are really the worst, I see at my work every day aswell.

And you can actually use programs for disabling telemetry or just turn it to the lowest (minimal) variant, so it works just like under 7 and 8, it sends only the crash reports to MS.
Or use Enterprise version and you can turn off EVERYTHING (I use a key I got from work for example) or Server version.

No difference in Ultimate or Pro unless you need a language pack, bitlocker or unix support

Thanks. Pro would be enough.
The store had both available just not at the same time. One day they had pro then the next time I was in they had no pro left but had one Ultimate for $10-$15 more. Ultimate option was just if they were still out of pro

Tried out Windows 10 on one of my machines, but quickly bailed out and reverted to Win7 and linux. I have no plans whatsoever to upgrade (downgrade?) to windows 10 after this.

Personally i would still recommend Windows 7 professional or ultimate, maybe in a dual-boot configuration together with Linux Mint.

Windows 10 was looking promising except for the spyware crap.
Thanks I'll get 7 pro.
Ultimate was available for not much more but I didn't need bitlocker or unix.
Was thinking about the dual boot option the other day.
Never tried Liinux before but have been interested in giving it try.

Thanks for input

Thanks.
I'll get Win 7 pro. Ultimate dvd was a option for not much more but i don't need bitlocker or unix.
Looked like win 10 was a step in the right direction until release.
That spyware is crap.

good choice, going with W7.
enjoy

Just a couple of advices:
- Check if the UEFI firmware has all the features needed to install Windows 7 in your motherboard documentation before spending money on that, with Asus you can usually download the original manual from the official site with ease.
- Just to be super-sure, try to Google-search the motherboard model and see how the Windows 7 installation went for other users.
- Get a SATA Blu-ray drive. I will do, anyway, even though I'm considering building my next badass PC around a Haswell CPU+Z97 chipset. Here in Italy Skylake CPUs still cost more than the previous Intel CPU generations, and Haswell is much more Windows 7 friendly anyway.

You can try this if you want to dual boot window 7 and Linux.
http://www.instructables.com/id/How-to-Dual-boot-Linux-and-Windows-on-a-PC-with-W/step2/Select-a-Linux-Distro/

Also Microsoft is pushing window 10 spyware crap on window 7&8 too, so you have to be careful not to update these window update, or uninstall them
http://www.ghacks.net/2015/08/28/microsoft-intensifies-data-collection-on-windows-7-and-8-systems/

Personally Linux Ubuntu acts like Window 7 except its function is at some other place, like the X to close the file is at the left rather at the right. Also you get a smaller collection of games that is compatible / optimize to it.
Still the number of Linux games are probably enough enough to last one lifetime.