If you're positive that a hardware problem isn't causing the Code 43 error, you could try a repair install of Windows. If that doesn't work, try a clean install of Windows.

How to Fix Your WiFi Repairing electronic devices can be frustrating. Here's how to quickly get help with slow signals, dropped connections, and other potential router issues.

Have you heard of a Mesh Network System? Instead of one router, it's 2 or 3 to strengthen the signal in your house.