I checked the fan and all programs installed/running without any problems or any strange applications.
What makes me worry is that the computer works normally in the safe mode.
How can I check the mining viruses?
First of all you should check if this problem also occurs if none of your wallets is running. I write this because in some wallets you can set (and forget?) to mine while running. Or maybe it can come set by default?
Also keep in mind that some websites or browser plugins also can mine.
Second, I suggest you run Process Explorer:
https://docs.microsoft.com/en-us/sysinternals/downloads/process-explorer It's made by a subsidiary of Microsoft.
If you leave it running, you'll see in the tray icon the CPU usage. And if it's on continuous high usage you can click and find the process that's using your CPU so heavily. And then you can research more about it.
Lately Windows Task Manager got better, but I use this program since the days TaskMan was not helpful at all.
Unfortunately if the bad program is GPU mining, this strategy will not find it. But you could tell what GPU you have, since there's a good chance you don't have a GPU that can mine...
Reset to factory is a bit extreme imho, also antiviruses may give you a lot of false positives (wallets too), but if nothing else works, ... it can be an option.
Most known antiviruses can be downloaded as CD/DVD image you burn and run from it so it can catch even the nastier viruses without the necessity to reset to factory. Just, again, beware of false positives.
I also recommend you backup all the wallets to make sure you don't lose your coins while trying out various things.