Intel Motherboards : constant freezes with asrock z170 extreme7+

If not, are you using any old SATA cables with the system? As a matter of course I always change mine whenever I replace a motherboard. 

Could you list the model number of your RAM too, it is helpful in determining any potential incompatibility. 

Some things to try:

Remove all drives from the system other than the one you plan to use as an OS drive (being sure you use a new SATA cable) and see if you still freeze.

Move the RAM into slot B1 and see if you have the same issue.

Remove all non essential USB devices from the system, including the front panel USB 3.1 cable.

Also try clearing CMOS using the battery removal method.

The issue is not POST related as the system is not displaying a post code and the freezing is occurring after the windows logo appears. Power On Self Test for anyone reading here who does not know occurs prior to the system attempting to boot.

Let us know how it goes and good luck.