You can try pinging your router for a few hours or a day and see if it drops your connection and for how long.
In the Command Prompt(Win+R>cmd) type something like "ping -t 192.1681.1"; if you don't know your router IP type "ipconfig" in Command Prompt, and it usually your Default Gateway(192.168.1.1 in my case). Press Control+C to terminate the ping test and get the results; dropped packets are a bad sign.
Alternatively, you can run a trace route in Command Prompt, "tracert taleworlds.com" to see if there are any unusually high pings between you and your destination IP.