Can access certain sites from ethernet but all from wifi

From any browser that I've tried (IE, Firefox, or Chrome), I cannot access certain sites using the ethernet connection, but have no problem using the wifi connection.

Two sites in particular are google.com and adobe.com.

I made the ethernet ip settings mimic the settings used by the wifi (disabled the wifi adapter of course).

I've checked device manager, and uninstalled / reinstalled the ethernet driver.

I've flushed the dns.

I've reset my hosts file.

I've reset the winsock.

I've scanned for malware using malwarebytes and superantispyware.

I've scanned for viruses using Avast.

I've found this old thread, but it didn't help.

I have reset the switch, but not the router. Only one computer on a network of 50 computers has the problem.

Thank you for your help.

Using a Windows 7 machine

 

Forgot to mention, I also checked and changed my proxy settings from automatically detect to no proxy.

 

Can you try using a different cable, ideally one known to be OK?

 

That did not fix the problem.

Just for further clarification of the physical environment, the computer is sitting on a workbench used for no other reason than computer repair or the like.
In this case, I was preparing the computer for a new department.
The previous department had no use for the internet, so the problem could be really old.
I had just successfully finished three other computers on the same equipment (cable and all) before this one.
I did go ahead and swap the cable, just to make sure.

Thank you for your reply. Please keep trying.

 

Still remembering other steps I've taken...

I've turned off Windows Firewall.

I've reset Internet Explorer to default settings.

 

The only other suggestion I would have would be to try to update the ethernet adapter driver from the computer manufacturer's website. I would not recommend using any of the many driver updating softwares around.

 

I guess it is possible the onboard NIC went bad?

The driver update didn't fix anything, and I just realized that I have to disable the ethernet NIC before the wifi can access all of the internet. It wasn't enough just to be on wifi.

This is weird and is making me feel very computer illiterate.

 

I have not checked the BIOS, but please remember that I can access some sites, just not all.
Would this be possible if the NIC is disabled in BIOS? Literal question, not a sarcastic response.

I have went to Dell and downloaded and installed all updated drivers, though.

 

I appreciate the responses, by the way. Thank you to both of you.

 

The fact that the adapter has to be disabled before the WiFi adapter can work does suggest either it has failed or there is some sort of incompatibility. If you have to have ethernet then a USB adapter would do the job.

 

I'll have to accept that it failed, and not imcompatible. Everything is on-board.

Thank you all, for your help.