Thanks Draetor already tried all and it looks like it's a chipset problem specifically related to Z170. There is another thread in the forums about an ACPI error with event id 56 causing freeze-ups. At first I didn't notice the error but after reading that post I checked and sure enough I had the error and is seemed to go off right before each freeze. Digging around some more I ran into this thread over at the Microsoft Support site, on page 4 there is a post where user Dean_peps quoted a reply from Asus saying it's a chipset issue, here's an excerpt:
"It's not related with driver/software. It could be confirmed on Z170 and B150 chipset motherboards, not only ours, but also other makers' motherboard."
There was a guy that went so far as to replace his motherboard with a different brand, replace gpu, psu and memory and still got the error. Now some users say they just see the error in event viewer and have no noticeable symptoms but others get the boot and reboot freezes or just random freezes.
Here is the link, give it a read.
http://answers.microsoft.com/en-us/windows/forum/windows_10-other_settings/windows-10-event-id-56/ae...I guess the Z170 platform is still too new. Eventually the board manufacturers will issue the fixes I suppose. For now I guess all I can do is tough it out.