Our Wi-Fi works perfect but on our desktop computer the internet isn't working. Everything else seems to be fine.
Computer is a Lenovo.
Added (1). The internet was working fine last night and this morning. Just suddenly a few hours ago it stopped working.
Forget you
The big question is, does your desktop have a built in Wi-Fi card? If not you would need a USB wireless adapter. There are 4 desktop computers here in the house, and only one has a built in Wi-Fi card. So with the others we're using a USB wireless adapter. Now if your does have a built in Wi-Fi adapter then try
Click Start
Control panel
Network and sharing
Click connect to a network
If your network name is in the list then highlight it,
and click connect.
place a check mark in the box that says Auto connect.
You're not going to get a good answer here. There are too many possibilities:
Network card
ethernet cable
proxy settings
malware
ip issues
firewall
etx