Shared network (no router) no longer functioning

[Calzinger]

Hello everyone. You all seem like smart people so here I go.

I currently have a network connection set up, but I don't use a router. I have dual ethernet ports on my motherboard for one computer. I connect my cable modem to that computer through one port and another computer to this dual-ethernet computer. I have a shared network connection on the main computer while the other computer uses its connection.

However, I noticed lately that the secondary computer is unable to get onto the internet. The connection reads fine at both ends. They are even able to transfer files among one another so the connection is good. It is just that the secondary computer cannot access the internet.

I believe it may be a virus on the primary computer.

I have had traces of WORM_ALCAN.A, but I haven't had any major symptoms. I couldn't even find have of the things the solution told me to look for so I assume that that isn't the problem. Anyway, I'm not even sure if I have it. But I do notice that I can't access the run -> cmd command, or most other run commands for that matter. That happens to be a major problem caused by the virus. Whenever I type run -> cmd or run -> regedit, I get this message: "C:\WINDOWS\System32\cmd.com. The NVTDM CPU has encountered an illegal instruction.". I would assume that the obvious problem is the fact that there is no cmd.com, but how can I even fix this? I have done virus scans to no avail.

That really was my initial impression. I assumed that there was some sort of startup procedure to actual network the connection that was bugged by thsi "cmd.com" garbage while in reality it should be cmd.exe.

I'm about to reformat my secondary computer, but I honestly doubt that will fix the problem.

I'm not really looking to reformat the main computer as I have too much data to back up (250 GB worth).

Any ideas guys?

Thanks in advance.

 

[Elbatrop1]

Did you set the 2 NICs to be bridged? Or did you go through the Internet Connection Sharing Wizard?

Post back and I should be able to help you with either of the situations.

 

[Calzinger]

I used the Internet Connection Sharing Wizard or that "Setup a home network wizard" dealio. But I do believe that it bridges the connections, noted by the "Bridged" label under the connections.

*
I just reformated my secondary computer and the problem persists.

 

[Elbatrop1]

Run ipconfig on both computers and post the results.

 

[Calzinger]

MAIN COMPUTER

Ethernet adapter Internet Connection:

        Connection-specific DNS Suffix  . :
        IP Address. . . . . . . . . . . . : 67.84.76.16
        Subnet Mask . . . . . . . . . . . : 255.255.248.0
        Default Gateway . . . . . . . . . : 67.84.72.1

Ethernet adapter Network Bridge (Network Bridge):

        Connection-specific DNS Suffix  . :
        IP Address. . . . . . . . . . . . : 192.168.0.1
        Subnet Mask . . . . . . . . . . . : 255.255.255.0
        Default Gateway . . . . . . . . . :

SECONDARY COMPUTER

Ethernet adapter Network Bridge:

        Connection-specific DNS Suffix  . : mshome.net
        IP Address. . . . . . . . . . . . : 192.168.0.27
        Subnet Mask . . . . . . . . . . . : 255.255.255.0
        Default Gateway . . . . . . . . . : 192.168.0.1

The puzzling part remains to be that both computers recognize the network. I can transfer files between each other through the network (through My Network Places for example), but that second one just refuses to connect to the net.

My assumption is that the problem is this "cmd.com" garbage on the main computer. Whenever I type "cmd" in start -> run, it actually runs cmd.com (which doesn't exist in windows) rather than cmd.exe. Read my initial post for more information on that.

I think there may be some sort of service or startup process that runs a cmd line or something but this ".com" trash messes it up.

I couldn't even type start -> run -> ipconfig on the main computer. I had to type start -> run -> cmd.exe and then type ipconfig.

Do you think that the fact that this thing bugs out so much with the "cmd.com" could be the issue?

**
I believe that this "cmd.com" business is fixed. After searching on the net for hours, I found a very helpful thread (link). The system was actually infected with a cmd.com file and a regedit.com file, but I couldn't see them in the system32 folder even when "show all hidden files" was on. I had to use the command prompt to find and delete them so the run commands work fine. I still have yet to find out if this has fixed the net problems, even though I may have a doubt.

**
That didn't seem to fix it. I am considering a reformat, but I would like to leave that as the last possible solution.

 

[Elbatrop1]

With your secondary computer, ping an external hostname, for example: www.google.com

If that works and you still cant bring up webpages in a browser, then it is a virus/spyware on one of the machines.

Steps to fix:

1) download, install/update a virus scanner (if you dont already have one). Also, download and install/update Spybot S&D and Ad-Aware. Do this on both computers.

2) Unplug both cables out of your dual-NIC computer (thereby unconnected everything).

3) Run your scanners and clean up any viruses or spyware.

4) Plug cables back in, and hopefully enjoy the internet again.

 

[Calzinger]

No viruses were found, surprisingly.

For some strange reason, I am thinking there may be a setup problem.

Do you think upgrading to a newer version of XP Professional will reset some settings that may have been changed by a virus? I'm currently running SP1, but can I upgrade to SP2 while keeping my files and potentially fix this?