Internet randomly cutting out.

I've been having this problem for a while now. My internet will randomly cut off but only on this PC. Sometimes the connection icon at the bottom right will turn to a yellow sign which means I need to reset my router or wait for it to come back but that can take upwards to an hour. Other times it will turn to a red cross mark and I need to restart my computer for it to come back. I thought it may have been my router at first so I upgraded and still had the problem. Then I thought it may be my ethernet cable so I replaced it and it still cuts out so my conclusion is that its a problem with the computer.

Any help is appreciated.