How can I tell if someone is remotely accessing my computer?

First off, I totally get where you're coming from. While you're waiting for more in-depth help, I recommend downloading an anti-malware program like Malwarebytes and running a full scan. It's a good initial step. If you're really concerned, consider disconnecting your PC from the internet after that to be safe. Hopefully, someone more experienced will jump in with better tips!

It’s possible that if you've logged into an account on another device, someone else might still be using it, which would cause those searches to show up. Have you checked to see if you’re logged into anything on other computers? Anyway, it sounds odd since you’re experiencing so many issues. Just in case, go to your Microsoft account settings and log out of all devices. That should help with any accidental access.

If this issue is happening consistently, keep an eye on the pattern of the blackouts and disconnect from the internet to see if it still occurs. However, since you mentioned that it happens randomly, that might complicate things. It could also be related to a hardware issue, like a faulty cable or power-saving setting.