Small office network file server and internet using Switch

Hi,
I am first time around here seeking help.
We are in a small office and are currently using one Desktop computer as a File server by sharing a folder using the existing WiFi from Internet router. This was done by connecting one LAN cable from the Router to the Desktop and the remaining computers connect to the router through WiFi. This way, each user could browse the internet while also having access to shared files from the central Desktop.
We are in the process of shifting to a new office where some users are seated far away, also the maximum connections possible in the router through WiFi is 16. So, we have laid LAN cables and got 2 Low cost network switches (unmanaged...TP Link 1024D). At the moment we are not planning to purchase a Server, but continue to use the same desktop. Instead of continuing to use WiFi, it is planned to make use of the new LAN cables and Switches.
The problem is if I connect the File sharing Desktop on Port number 1 in the Switch, I will not be able to use internet in the computers connected through LAN cable (and vice versa). I need to use Internet as well as shared files from the Central Desktop.
Thanks in advance.

The port number on the switch does not matter. If you connect the switch to the router, then all computers connected to the switch should have access to everything including the Internet.

What are you seeing?

Are you missing a default gateway in the wired PCs' network settings?

Do these PCs still have their wifi enabled at the same time as being plugged in to the switch?

On one of the problem PCs, open a command prompt, type ipconfig /all and show us the output of that. Do the same on the central desktop.

*You can open a command prompt from: Start/All Programs/Accessories/Command Prompt

pbcopter said:

The port number on the switch does not matter. If you connect the switch to the router, then all computers connected to the switch should have access to everything including the Internet.

What are you seeing?

I tried to connect the LAN from Main Desktop in Port 1 and internet LAN to another port. It works but it appears that the internet speed is considerably slow. However, if I connect the internet LAN to port 1 and Main Desktop to another port, then internet seems to be in the normal speed. I am yet to test with all connected PCs.

Will soon check and reply. Thanks to all for their suggestions.

Thanks to all replies. Actually we had an issue with a faulty Switch, which has now been replaced.
The network is now operational and internet also works on original speed.