New Lenovo lappy will not connect to my wifi

My HP laptop gets my wifi signal fine, 5 bars in the living room. The Lenovo was showing only 2 bars and was unable to connect. I put it right next to the router. Unable to connect again.

What do I do?

I have a TP Link Archer C7 router.

What model?
What OS?
Updated drivers?

Tried everything, called tech support they said she's defective. Back to the store tomorrow. New laptop will be had.