Have you had any luck in sorting your problem?
I've found this thread as I have exactly the same problem except I'm testing a 4790k in an HP 800 G1 SFF & a Dell Optiplex 7020 SFF with Windows 10 x64. Overclocking isn't the aim: I just want the performance increase that this cpu has as standard.
The result is the same with either: as soon as the Intel video driver is installed everything freezes up within 30 seconds or so but will work in either Safe Mode or with the 'Microsoft Basic Display Adapter' driver installed. I've tried various versions of the Intel driver from Intel, HP and Dell respectively but always get the same results.
I can boot a PE based rescue environment and run stress tests and all seems ok but if I try to boot an Ubuntu Linux iso it freezes as with the Intel driver in Windows even if I select the 'safe graphics' option.
As I wrote this, it got me thinking: Since this freezing is a symptom of too much undervolting, could the Intel driver be doing just that and either the 4790k doesn't like it or my individual example is degraded slightly and can't cope....?
To test this, I've installed 'ThrottleStop' and overvolted the 'CPU Core', 'Intel GPU' and 'CPU Cache' by 85mV and it finally runs without issue. The trickiest part was getting ThrottleStop to start quickly enough - if done manually the system would often freeze too quickly to logon and start ThrottleStop so I've got Task Scheduler running it as 'System' user at startup rather than logon and it seems to be reliable. Now I'm going to reduce the voltages to the lowest level that I can get away with - maybe I'll just need to increase the Core or GPU voltage alone.
If it freezes, the way to change ThrottleStop is to start in Safe Mode and edit the ThrottleStop.ini file directly - fiddly but it works. In theory I'd use Intel XTU but apparently there are problems with making the settings load at startup so I haven't tried this.
Ultimately I'd like to try to unlock hidden menus in the HP BIOS and make these adjustments there but don't know if it's possible - any advice welcome but I figure it's a subject worthy of a separate thread - unless anyone is aware of a way to control the amount of undervolting performed by the Intel driver at all?
All the testing is being done on the Optiplex 7020 at the moment but I want to end up with the 4790k in the HP.
Hope this helps.