I already noticed it for weeks maybe but I thought that I was just overthinking. But today, I am sure that every time (not always but most of the time especially now) I turned on my PC, there is no internet connection (both cable and WiFi) or about 10 minutes, the internet will be lost. Yet, if I turned off my PC, the internet connection comes back after a few seconds. I am sure that this is the case because I had no internet connection for hours already when my PC is turned on and vice versa. I tried to install/reinstall the ethernet driver or restart the PC/modem/router but it doesn't help. I'm really thinking there's really a problem between the connection of my PC and the router/modem.

Please help me. I only have little knowledge about tech stuff. Thank you in advance!