I guess the real question is: What kind of router do you have?

A single band router operating on a 2.4ghz signal can receive interference from quite a number of things. Certain building materials, multilevel homes, glass partitions and household devices that operate on the 2.4ghz frequency like microwaves, baby monitors, and cordless phones can all degrade wireless performance. Dual band routers that offer the 5ghz channel can offer better stability in cases like the above.

It could also be a router with a poor signal. But if both the PC, and the Laptop are the same distance, and one has a good signal and the other doesn't. You can assume in that case that the issue is not with the router.