Network says it's connected, but it's not

I've got a computer that can't get online. There are many things I've tried, but this one's pretty tough. The computer says the LAN is connected, and the network adapters are functional in Device Manager. Here is a list of things I've done/checked:
*Checked basics like "Automatically detect settings" under LAN settings and Obtain IP Address Automatically and Obtain DNS Server automatically.
*Used IE and Chrome, and tried updating programs online.
*Other devices connect fine to router. I tried powercycling both the router and modem. The computer also has a wireless PCI card, so I tried that as well. It shows as connected, but still nothing. Also tried different router and modem. I can't get into the router settings either. Also tried different ethernet cables.
*Ran malware scans with Spybot and Malwarebytes. Couldn't update Malwarebytes, got "database is missing or corrupt" error.
*Ran AVG Scan
*Tried Safe Mode with Networking
*Winsock fix
*lspfix
*System Restore
*Turned off Zone Alarm
*Temporarily disabled AVG
*Network Diagnostics gives "Contact the company that provides you Windows XP Product Support"
*Commands: netsh winsock reset catalog, netsh int ip reset reset.log, ipconfig gives "An internal Error occured. The request is not supported.
*Thought maybe AVG moved a network file to virus vault so I restored some infected files.

Any help is much appreciated.

 

http://majorgeeks.com/geek_search.h...1&ie=ISO-8859-1&q=tcip+repair&sa.x=24&sa.y=12
Did you update drivers????

 

If you got this message it sounds like you have a completely dead TCP/IP stack. Nowadays the rootkit ZeroAccess has been causing this.

Here is my recommendation as it has worked for others:

Here are the steps to resolve this:

I would like you try the below.

Click Start, and then click Run.
In the Open box, type regedit, and then click OK.
In Registry Editor, locate the following keys, right-click each key, and then click Delete:

• HKEY_LOCAL_MACHINE\System\CurrentControlSet\Services\Winsock
• HKEY_LOCAL_MACHINE\System\CurrentControlSet\Services\Winsock2

When you are prompted to confirm the deletion, click Yes.
Close the Registry Editor.

Locate the Nettcpip.inf file in C:\WINDOWS\inf and then open the file in Notepad.
Locate the [MS_TCPIP.PrimaryInstall] section. Change the Characteristics = 0xA0 entry by replacing 0xA0 with 0x80. Save the file. Exit Notepad.
In Control Panel, double-click Network Connections, right-click Local Area Connection, and then select Properties.
On the General tab, click Install, select Protocol, and then click Add.
In the Select Network Protocols window, click Have Disk.
In the Copy manufacturer's files from text box, type C:\WINDOWS\inf, and then click OK.
Select Internet Protocol (TCP/IP), and then click OK. It will report as unsigned, this is the one we want! Do not choose Microsoft TCP/IP v6!

Note This step returns you to the Local Area Connection Properties screen. However, the Uninstall button is now available.
Select Internet Protocol (TCP/IP), click Uninstall, and then click Yes.
You will be asked to reboot your PC for the changes to take affect, go ahead and do this now.

Once you have rebooted...
In Control Panel, double-click Network Connections, right-click Local Area Connection, and then select Properties.
On the General tab, click Install, select Protocol, and then click Add.
In the Select Network Protocols window, click Have Disk.
In the Copy Manufacturer's files from text box, type C:\WINDOWS\inf, and then click OK.
Select Internet Protocol (TCP/IP), and then click OK.
Restart your computer.
Test your Internet connectivity.

____________________________

If that worked, then I would highly recommend checking for malware by going through this thread: READ & RUN ME FIRST Malware Removal Guide

 

There is no "inf" folder in my Windows folder...

 

Sorry, noob move, inf is hidden, duh. My bad, lol.

 

Ok, got through the steps. It didn't work. However, I think I've found the culprit. When I was checking services, and noticed that DHCP, DNS, etc. were not started, I went to device manager, clicked "show hidden devices" and under non-plug and play devices, "IP network address translator" and "tcp/ip protocol driver" had yellow exclamation marks on them. I uninstalled tcp/ip protocol driver thinking that it would reinstall it automaticallly on reboot, but it didn't and now I have no tcp/ip protocol driver in device manager, and still can't get online.
I know I've caused more trouble, but at least we know the problem now. Again, any help is greatly appreciated.

 

sfc /scannow did the trick!

 

Glad to hear you got it working