Windows 10: KB4512508 and app's crashing

Ok so I figured out how to cure the KB4512508 not installing (in place upgrade with .295 ISO), but since then I've been getting a lot of crashes in games and app's running full screen.
Thought at first my GPU had developed a fault but after having run several benchmarks and GPU burn in tests which all ran perfectly, even Unigine's superposition at 5k settings, because that uses over 5Gb of v-ram, which ran without issue for over half an hour, I went to Nvidia's forums and there are quite a few people there with similar issues that started after this KB update.
Even app's like Blender crash if run full screen.
All the games and apps run windowed with no issues. The benchmarks and burn in's I think must use their own internal draw methods, bypassing Nvidia's, because all run full screen with no issues.
Was unsure where to put this post, gaming or general, cause it's sort of both.

:)

 

all games crash!

I suggest you run rthdribl > http://www.daionet.gr.jp/~masa/archives/rthdribl_1_2.zip
Increase the window size step by step and watch your vga temps permanently.
What happens?
If it crashes, run at stock speeds as suggested before and retry.

P.S.: When your system locks, does the display signal turn off after a time?
Stuttering sound or no sound at all when freezing?
What X1800XT model do you own exactly?

 

all games crash!

ive watch my temps and both the cpu and gpu are within normal ranges. when it freezes it simply freezes the image and stops the sound. i must reboot to get back to windows.

 

Mail app crashes when turning off conversations

Hi Gareth,

To assist you better, kindly provide us more details by answering the following questions:

• Are you getting any error messages before the Mail app crashes?
  
• What specific troubleshooting steps have you tried so far?

Meanwhile, we suggest that you run the Windows app troubleshooter from this
link.

Should you need further assistance, feel free to get back to us.