First post, and desperately looking for a way of solving this issue, so I hope you don't mind me asking here, where wise users may know obscure solutions! Right, here's the basics; my system started becoming unusable recently. At first, I thought I'd found the solution, in Windows 10, I found SleepStudy was writing itself to disc endlessly and locking up my system. I've contacted Microsoft about that, and they're aware of it, but have no solution. I have to keep setting the file to Read Only every time and restart to make it stick. But I was still noticing problems with my machine over time. Only now it's CPU usage, with CPU 0 in particular being hammered to 100% constantly. It's not every time, once or twice I can start the machine and it runs clean, but it's there let's say 9/10 times. I've googled around, and found instructions to try and narrow down what it is, and as far as I can see, it's notskrnl and the Service Host Diagnostic Policy reporting some sort of error endlessly. What I can't tell is what is causing that. And here's where it gets frustrating. This is what I've done since; Updated every driver I can find Rolled Windows back to a repair Done a clean reinstall of Windows Done a Virus and Rootkit scan on the clean install, nothing. Disabled everything except core parts of Windows under Device Manager, problem persists. Checked connections, looked for damaged parts on the motherboard Ran RAM check, no issues Ran drive checks, no issues Watched temperature sensors, machine is running cool Checked voltages; I'm not an expert HWinFO64 seems to show they're normal. Both the SleepStudy issue, and the CPU one persist even with that fresh Windows install. I'm leaning towards it being a hardware fault, but I have no idea how to go further from here. Thinking about it, it could also be with SleepStudy set to Read Only, it's endlessly error reporting its attempts to write to it... Hnnngh. I've run a High CPU trace, which can be downloaded here, but I've no idea how to read it deeper to locate where that CPU use is coming from. Can anyone help, please?