Two laptops, same house, same wifi network, very different pings

I just got a new laptop. It is connected to the same Wi-Fi network at my home as my old laptop. They are sitting right next to each other. But my original laptop has a ping in a game I play (Overwatch) of 20ms, while my new laptop (a much better machine in every way I know how to measure) has a ping of 200ms, which is resulting in unplayable lag.

What could be causing the difference, and how might I fix it?

Additional info:

“ping google.com” in the cmd line gives identical pings for the two machines.

However: pingtest.net gives very different results! 20ms or so for my original laptop, 150ms or so for my new one.

I do not know what this means, and I don’t know what to do about it.

Disable your wireless security and retest.

I had already gotten rid of the pre-installed McAfee but I’ll try it without Windows security as well.

(Unless I have just fixed it by getting rid of a piece of bloatware I’d missed–a game streaming app, which I have seen here and there sometimes causes high ping to happen…)