My desktop pc won't connect to my wireless interenet anymore...but it connects fine to my router? Help!?

[KatieS]

I have a 4 year old dell computer running windows 7. My router used to work fine until we added a third computer to the network. Now my mom's computer (it's hardwired to the router) can connect just fine, but my computer has no internet. All my drivers are up to date, and my computer is connecting to the network, but not the internet. How do I get my internet on my computer again???

By the way, the third computer we tried to add to the network...that didn't work out at all.
I have scanned my entire computer three times with different AV and malware detectors and removed all threats.

[Steve B]

Scan for spyware. Malwarebytes Free or SuperAntiSpyware Free - or check if you have 3rd firewall software installed (e.g. Norton Internet Security). Either could block network traffic.

[Sean]

did you try to plug the Ethernet cord into the computer?

try it,it should work