do you mean the power supply? Yes I thought about the power supply in wife computer.

How do I check the ethernet adapter IP address conflict - via ipconfig? Do I then need to check the IP's of all the other devices in the house? Yes you are right. Also if a conflict, how do I change...

Curious reason :)

Maybe your computer may emit some noises (exactly AC)

It's possible in openwrt/gargoyle.

You can try on other internet browser.