Some time internet router connect with lptop and some time not

Aslam u alikum, my laptop is giving problem that it shows good signal of internet router but some time website did not open of my laptop but at same time my friend laptop working on that same internet router whenever its laptop showing week signal and my laptop showing strong signal. some times it connect with my router and some time not whenever i'm alone or some time 2 persons users of it at that time. i don't think it is hardware problem otherwise it should not run internet some time. some time i try to connect a lot of times then it connect with router and some time not and after some time it automatically connect