Could you please be a bit more specific?
You mention that you installed a new wireless network card, and it doesn’t work...
Do you have any yellow icons on Device Manager? (If Windows Used)
What operating system are you using?
Can you ping 127.0.0.1?
Do you get an IP address from the Router?
Is MAC Filtering Enabled on the Router?
Why you want to fix the Ethernet without uninstalling the wireless driver?
Find below a link were you will find the latest drivers for you wireless card.