Hi mymnymny,
If the wireless card does not show in Device Manager under networks - and you have no unknown devices showing - I would think that the issue would be with the wireless card or the motherboard. If you installe another wireless adapter in the notebook - and Found New hardware Wizard does not run - then you can purchase a USB wireless adapter - so you have two chances as I see it to get wireless access on that computer.
I would borrow a friend's internal wireless card if possible - and be careful how you handle the wireless card if you can gain access to one. That way you could rule out your motherboard as the problem if the Add hardware wizard ran - you would likely suspect the motherboard if the wizard does not run - computer does not detect a new card.
Of course - be sure and ground yourself so as not to discharge any static electricity to the component. I'm sure you can Google that to find more info if you are not familiar with working on computers.
Best of Luck.
Chronk