There's good advice here for folks who need a "Whole house" solution, but it looks like the OP needs just a little boost for his laptop. I have used several WiFi adapters in the past, and the best so far has been a BearExtender. I have the TP-LINK adapter that Fizz mentioned and it works well. The BearExtender has a much higher power output.
If all that is needed is a little boost, pretty much any external adapter should work. Add a USB extension cable and mount the adapter in a location where you get a consistent connection.
The BearExtender is available on Amazon for $34.97:
https://www.amazon.com/Bearifi-BearExtender-Booster-Extender-Microsoft/dp/B017KVVH76/ref=sr_1_3?ie=UTF8&qid=1522576422&sr=8-3&keywords=bearextender