Lost internet connection after Service Pack 4 installation

Reset TCP/IP:
 Start->Run->CMD <enter>
 at the prompt, type:

 netsh <enter>
 int <enter>
 ip <enter>
 reset all <enter>

Also try Winsockfix:
 Download and run the following:
 http://members.shaw.ca/techcd/VB_Projects/WinsockFix.zip

Tried both suggestions (thank you by the way, for such a prompt response).  Unfortunately, I get an invalid command message at reset all and installed the winsockfix, but still unable to connect to the internet.

Any other ideas?

Go into Control Panel/Network
and remove your network adapter there.
Reboot and allow Windows to reinstall it.
The default settings should work.

Is this a home network?  How many machines?  Using a router?  DSL, Cable or Dialup?

Do have the correct driver for your NIC? What brand of ethernet card do you have?

If you dont have correct driver for your NIC youll have to goto the manufactuers website and get it.

This is a home computer but not on a network.  Using a hub to share a cable modem.  Other computer is having no connection problem.  No matter which Service Pack we try to install, the same result occurs, no internet connection.  Cable company provider can find nothing wrong at their end and nothing wrong in the TCP/IP setups.  

Removed the TCP/IP, File and Print Share and the Microsoft Client from the Control Panel/Network.  Upon rebooting, Windows did not ask for new hardware installation.  Reinstalled via Control Panel/Network screens.

Should we try to remove the network adapter through add/remove hardware and then reboot to see if Windows reinstalls?

Answer to PlatinumStylz...

Ethernet card is built into the motherboard which is an ASUS VIA KT 400/KT333 SERIES

Correct driver is installed.

Yes, Start->Run->Devmgmt.msc
Remove the adapter and reboot...

(technically, you 'are' on a network if you're using a hub with 2 or more computers... :D)

Ok, removed the adapter and rebooted, still no internet connection.  Recognizes the ethernet card, but no internet connection.  When the Service Pak's are removed, we can connect to the internet just fine.

>>When the Service Pak's are removed, we can connect to the internet just fine.<<
Odd - very odd.

Reinstall SP4.
Reboot
Then
Click Start->Run->SFC /Purgecache
Start->Run->SFC /Scannow
Reboot

Results?

We are in the process of doing the /Scannow and are finding a problem.

We are repeatedly receiving the following prompt:

"Files that are required for windows to run properly must be copied to the dll cache.  Insert your Windows 2000 Professional CD now"

When we insert the CD we get the following prompt:

"The CD you provided is the wrong CD.  Please insert the Windows 2000 CD into your CD ROM drive"

I assure you we are inserting the only Windows 2000 Pro CD we have and that when I check the CD on my computer, it has no problem reading it.  Also, the computer in question has no problem reading any other CD.

We are trying to work through the numerous prompts and will be with you shortly..in the meantime, any clues why it is saying this is the wrong CD?

We finally got past the file checks, but the pop up shut down before it completed, after countless cancels in answer to the prompt to insert the CD, since it wanted some CD we apparently don't have?

Each time we uninstall the Service Pack's, the computer is fully restored for internet connections.  Each time we reinstall the service packs, we lose the ability to connect.

No internet connection after completing (if you can call it that) the /Scannow

Yikes!
Forgive me...
Reinstall SP4 should read
Uninstall SP4...

Now try SFC
(http://support.microsoft.com/?kbid=222471)

You should reapply SP4 afterwards...

No problem.  Uninstalling now and then will try the SFC

Thanks for hanging in there with us.

My pleasure... :D
-although 'bedtime' is rapidly approaching I'm afraid :'(

I understand.  We can always try again tomorrow and leave the service packs uninstalled this evening.  Am rebooting now and then will be doing the scanpurge and scannow and advise momentarily

Completed teh scannow and nothing happened at the end...

So, we are trying a reinstall of Windows 2000, the install that does not overwrite settings or programs....

Maybe that will fix this.

Will let you know what happens.

My apologies on the netsh (I'm using XP).
This should work under 2k to reset TCP/IP:

netsh
interface reset all
routing reset all
routing
dump
bye
exit

Reinstalled Windows, reinstalled Service Pack 4, no internet connection.

Followed the above for resetting TCP/IP.

No Internet connection.

Uninstall Service Pack 4....connects fine.

Am at a loss.

What else are you running on this server?
Perhaps it's an incompatability issue with SP4 and another product?
Firewall for instance...

That is very odd.........

You might have a virus, maybe the blaster virus
http://www.microsoft.com/security/incident/blast.asp

Are your LAN IP's conflicting?

Goto Start/Run type "cmd" a dos prompt box will open. type "ipconfig" what ip address comes up? Are you getting a legitimate Ip address?

Virus definitions are updated daily and scans are run nightly, so no viruses on the puter.  This is a brand new drive, recently reformatted, only problem is that the updated Service Packs weren't installed before putting other programs on the hard drive.

We updated the LAN driver tonight and ran a diagnostic...if we install ANY of the Microsoft Service Packs, after installation the diagnostic tells us that the LAN is not detected.  If we uninstall the Service Pack, the diagnostic comes back with no errors.

We've just about given up and decided to reformat, put 2000 back on, immediately install all service packs and then install all programs.  We run a firewall, pest program, trojan detector and spy blocker in addition to Norton, so is very possible one of these has caused the problem...although we did uninstall each and every one of them today, installed Service Pack 1 and we were back to square one again.

Sometimes you just gotta give in and reformat *sigh*.

Thanks for trying to help us though.

No Problem,

Just a thought, when you reformat, try and install the service packs via windows update before you install other programs.

Yep..thought of that and we are up, running, connected to the internet with Service Pack 4 installed and now busily restoring the drive with programs.

Hurray!
Glad you got it working sinamin...