johnbl :
if you can boot, then start cmd.exe or powershell and run
dism.exe /online /clean-image /restorehealth
I think one of the things it does is repair the windows component store (WinSxS folder)
Dism.exe /Online /Cleanup-Image /AnalyzeComponentStore
(might tell you what is wrong with component store but I have never used it)
if changing the GPU timing had any effect I would be looking to update the motherboard sound drivers.
versions that came out in 2017 tend to work while the older versions would crash the GPU sound driver and crash the GPU
(update motherboard sound driver from the motherboard vendors website)
This is what i get when i type in dism.exe /online /clean-image /restorehealth
Microsoft Windows [Version 10.0.17134.165]
(c) 2018 Microsoft Corporation. All rights reserved.
C:\Windows\system32>dism.exe /online /clean-image /restorehealth
Deployment Image Servicing and Management tool
Version: 10.0.17134.1
Image Version: 10.0.17134.165
Error: 87
The clean-image option is unknown.
For more information, refer to the help by running DISM.exe /?.
The DISM log file can be found at C:\Windows\Logs\DISM\dism.log
And this is what I got when I typed Dism.exe /Online /Cleanup-Image /AnalyzeComponentStore
C:\Windows\system32>Dism.exe /Online /Cleanup-Image /AnalyzeComponentStore
Deployment Image Servicing and Management tool
Version: 10.0.17134.1
Image Version: 10.0.17134.165
[==========================100.0%==========================]
Component Store (WinSxS) information:
Windows Explorer Reported Size of Component Store : 8.67 GB
Actual Size of Component Store : 8.24 GB
Shared with Windows : 5.72 GB
Backups and Disabled Features : 2.33 GB
Cache and Temporary Data : 192.31 MB
Date of Last Cleanup : 2018-04-12 01:45:02
Number of Reclaimable Packages : 0
Component Store Cleanup Recommended : Yes
The operation completed successfully.
And I am running latest audio drivers from gigabyte. Also, I am getting new BSOD which sais SYSTEM SERVICE EXCEPTION when on stock clock on GPU.
edit: I also tried to reinstall windows and create new windows installation and install it again, but still same problems.