Ok, I really need help with this one since I am fairly new to networking.
My goal is to be able to login with a few laptops and be able to access internet and our file server's hard drive.
However, I purchased a wireless router and simply plugged this into the main router which allows internet access but does not allow access to other wired computers. If I directly plug the server into this wireless router with this router being wired to the main router, then the wired computers cannot access the server. It's as if it creates its own little network. So, I connected this directly to the main router which gives internet access but nothing else.
(Note: I cannot simply install a new main router.)
I believe I need a wireless access point, but I'm not certain. Any ideas or suggestions???
You stumbled upon the truth. Simply plugging one router into another (WAN to LAN) creates a new network!
When chaining routers, you need to connect them LAN to LAN, then disable the DHCP server on the second router, and assign a static IP to the second router that's in the same subnet as the first/primary router (so if the primary is say 192.168.1.1, perhaps make the second router 192.168.1.2). That turns the second router into a simple WAP (wireless access point) + switch.