Block Access from a Wireless Network

Hello,
I would like to know if it is possible to restrict secured wireless internet access to specific laptops. Here is the scenario – A co-worker and I have had wireless access for a couple days and after that zilch. We are detecting the network but even after entering the key still cannot get access. I brought a brand new laptop to the office to see if I would be able to detect and connect. I detected it, entered the key and connected successfully. Still no access on the other two aforementioned laptops but other departments have access 24/7. How is this possible?