How do I network computers in two rooms wirelessly but still use ethernet cables going into all the actual PCs?

I currently have one office with a wired network and am about to get a second office room across the hall. But I'm not allowed to drill holes. How can I hook up computers in the new room to join in the existing wired network we have and access our file server without running a cable across the hallway (and still use wired computers in the new room)?How do I network computers in two rooms wirelessly but still use ethernet cables going into all the actual PCs?
Set up a 'Wireless router' like the Linksys WRT-54G in the 'wired office. Get another one or an Access Point and put that in the 'un-wired' office. You can then use a wire to that router or access point and have it broadcast to the other one and to the internet.





Use the strongest encryption that the routers and devices can support.How do I network computers in two rooms wirelessly but still use ethernet cables going into all the actual PCs?
use 2 routers.....1 for the server that has the internet connection


1 for the client