Virus caused TCP/IP Problems

Ok... Your PC was FULL of viruses and spyware. Boo!!! But, You've managed to successfully remove them... Hurrahhh!!! Well, upon reboot you now can no longer get to the internet.. Boooo!!!

Dropping to a command prompt and doing an ipconfig returns this wonderfully cryptic information:

I found this solution from: http://forums.scotsnewsletter.com/lofiversion/index.php/t9743.html This worked very well for me when I gave it a try.

To fix the problem, you have to replace TCPIP.SYS with a good copy. Reinstalling Windows will not allow you to replace it. Starting in Safe Mode Command Prompt won't give you the ability to rename or delete TCPIP.SYS. Starting Windows from the CD and using the Repair Console will also fail unless you follow this set of steps.

1. Get a copy of TCPIP.SYS by searching "TCPIP.SYS" on your machine, looking in hidden files and folders. You'll get a bunch of hits. Right click the files and check the preferences to get the most recent version that has Revision data from Microsoft. The one in C:\windows\system32\drivers is not gonna have any file data associated with it, even though it is exactly the same size as the good file.
2. Put the copy of TCPIP.SYS on the root of your C: drive. I had a problem when I made a folder for it, so I recommend just copying it directly to root.
3. Restart your computer with a Windows XP CD (WIN2000 would also work, I think) and select the Repair console function. Log in as Administrator (better know your administrator password!).
4. Navigate to C:\windows\system32\drivers. You will be able to see the TCPIP.SYS file there is you type in DIR, but you won't be able to delete or rename it.
5. Type in "CHKDSK /P". This runs a disk check on your hard drive and fixes errors whether the System thinks you need it or not.
6. Type "del TCPIP.SYS" and press Return.
7. Type in "CHKDSK /P" and run the disk check again (yes, I tried to do do this without this step the first time and it didn't work).
8. Type in "copy C:\TCPIP.SYS". You should get a message that this completed correctly.
9. Type in "CHKDSK /P" one last time just to be sure (I didn't confirm that this was required, but why waste all the previous effort?)
10. Type in "Exit" and let the computer restart. Your internet access should be restored, the Windows Firewall will work, and ipconfig should be able to config IP.

Good luck, I hope this helps if any of you run into this problem.