The Internet stopped working on my PC

Hi everyone! Here's the problem: three months ago, I started having internet issues at home, and rebooting the system solved them. A technician came and fixed it. Everything worked fine for everyone else, but my PC's internet connection went dead. I literally type one query in the browser, like "hello," and then the internet goes dead. It shows there's internet, but in fact, there isn't. Using a cable doesn't help, and changing the Wi-Fi adapter doesn't help. Clearing the DNS cache doesn't help. I'd be grateful if anyone could help.