Sharing a Cable Internet Connection without using a Network Switch.

There are two computers at home; one used by my brother (say PC1) and the other by me (say PC2). There's only a single Internet connection, via a cable modem (which was previously connected directly to PC1's network card).

The cable company registered the MAC address of PC1 into their database, so any other computer or network card may not be used with the connection, without first talking to them.
 I wanted to share the Internet connection between the two computers using the cheapest possible method. I put a second network card in PC1 and connected PC1 and PC2 with a simple crossover network cable. Then, I gave an IP of 192.168.1.1 to PC1's second network card and 102.168.1.2 to PC2's network card.

The network connection status on both computers showed as connected. After checking the connectivity, using the ping command, I started the 'Network Connection Wizard' from the network connections (in the control panel), on both computers. On PC1, I enabled the first option in the wizard because PC1 was directly connected to the Internet. On PC2, I enabled the second option because it would connect through PC1.


Sharing the Internet connection is very simple in Windows XP. Without putting any proxy settings or changing any other settings, I was able to browse the Internet and use all other Internet services that I needed, without any problems, on PC2.

 A problem occurred, when PC1 was switched off and I still wanted Internet access on PC2. A simple solution to this was to extend and connect the cable modem's network cable, directly to PC2, when needed. This would be a hassle every day, sometimes more than once. This also needed me to change the MAC address of PC2's network card. So, I thought of something that wouldn't need me to buy a network switch with eight ports (which is expensive for use with just two computers).

I did a little trick. Actually, not a trick, but Windows has this as an option for each network card. First, I changed the MAC address of PC2's network card to be the same as of PC1's first network card (which connects to the cable modem). I used the free little program called "MACAddressChanger" to do this. Then, I opened the network card's properties and removed the 192.168.1.2 IP that I gave it earlier. I then set the IP and DNS to auto configure. I set the 192.168.1.2 IP on the alternate configuration tab.

Now, when PC1 was switched off, I would just connect the cable to the modem's network port. And, when PC1 would be on, I would switch it back to PC1's second network card. PC2 would always detect what IP it had to use. I could use a four-pole, two way switch to switch the connection easily, but this method is okay and still easier than connecting the cable from the modem to PC2 and changing the configuration settings every time.

Resolving the "Unknown Device" error in Windows XP / 2003

This "Unknown Device" can be seen as a yellow question mark if you open the Device Manager. There may be more than one device under the question mark.

Sometimes, Device Manager is able to detect what the device is. At other times, it cannot detect. If you are lazy to open the computer to find out, use this simple method.

Most of the time, the device would have a unique ID burned into it. This ID can be used to find information about the device.

How to find this ID:

Open the Device Manager.
Open the properties for the "Unknown Device" and then click the 'Details' tab. Select 'Hardware IDs' from the drop-down list. There will be many lines of junk. You only need the first line. It contains all the information needed to find the correct driver.

Unknown Device Identifier is a small freeware from Huntersoft, which identifies unknown devices, not recognized by Windows. It searches working drivers on the Internet and contacts hardware manufacturers or vendors directly.

It comes in handy when you reinstall your operating system and cannot figure out what to do with all those devices with yellow question marks in the device manager.

Unknown Device Identifier is a nice program. It's easy to use and is a great help to people who need to install drivers for undetected devices on their computers.

Windows XP Crash Recovery – when all else fails

Unless you are using another computer to view this, it would be better if you print out these instructions. You would need to type many commands, later. I’m typing a detailed procedure on how to recover your non-bootable Windows XP.
It’s possible that somehow your Windows registry got corrupted. But there is a backup. The only thing you need to do is to manually restore it. How do you do that? Follow the procedure below.

Boot your computer using your Windows XP CD in the drive and press enter when it asks to boot from CD (if it does not ask, then you will need to go to the CMOS setup by pressing DEL or F2 key and change the boot sequence to boot from the CD Drive).

Now, when booting from the XP CD, when you are asked if you want to do a recovery, press R and you will get this screen:
Microsoft Windows(R) Recovery Console

The Recovery Console provides system repair and recovery functionality. Type EXIT to quit the Recovery Console and restart the computer.

1: C:\WINDOWS

Which Windows Installation would you like to log onto (To cancel, press ENTER)?


Type 1 and press enter.

Now type the commands I am putting below, one by one per line and press enter after each command:.

md c:\tmp
cd system32\config
copy system c:\tmp\system.bak
copy software c:\tmp\software.bak
copy sam c:\tmp\sam.bak
copy security c:\tmp\security.bak
copy default c:\tmp\default.bak
del system software sam security default

(The system will reply with appropriate messages after every command above, like “1 file(s) copied")

Now, type these commands, one per line and press enter after each (Take care to type the dot as it is):

copy c:\windows\repair\system .
copy c:\windows\repair\software .
copy c:\windows\repair\sam .
copy c:\windows\repair\security .
copy c:\windows\repair\default .

Now type exit and press enter and the system will reboot.

Remove the CD and boot into Windows normally, as you do before.

If the system boots in to Windows, then do the following:

Start Windows Explorer.
On the Tools menu, click Folder Options.
Click the View tab.
Under Hidden Files and Folders, click to select Show Hidden Files and Folders, and then click to clear the “Hide Protected Operating System Files (Recommended)” check box.
Click Yes when the dialog box is displayed that confirms that you want to display these files.

Double-click the drive where you installed Windows XP to get a list of the folders (This is most probably, the C Drive). It’s important to click the correct drive.
Open the System Volume Information folder by double-clicking it. (This folder appears dimmed because it is set as a super-hidden folder.)

This folder contains one or more _restore {GUID} folders such as “_restore{87BD3667-3246-476B-923F-F86E30B3E7F8}”.
Open a folder that was not created at the current time. You may have to click Details on the View menu to see when these folders were created.

There may be one or more folders starting with “RP x" under this folder. These are the restore points. Open one of these folders to locate a Snapshot subfolder.

The following path is an example of a folder path to the Snapshot folder:

C:\System Volume Information_restore{D86480E3-73EF-47BC-A0EBA81BE6EE3ED8}RP1Snapshot

From the Snapshot folder, copy the following files to the C:\tmp folder with the mouse (by Ctrl-clicking them):

_registry_user_.default
_registry_machine_security
_registry_machine_software
_registry_machine_system
_registry_machine_sam

Now, once again put your XP CD in to your CD Drive and reboot the computer.

Again press R for the recovery console when you see the message for recovery.
At the console, type these commands one by one per line and press enter after every command:
cd system32\config
del sam security software default system
copy c:\windows\tmp\_registry_machine_software system
copy c:\windows\tmp\_registry_machine_system system
copy c:\windows\tmp\_registry_machine_sam sam
copy c:\windows\tmp\_registry_machine_security security
copy c:\windows\tmp\_registry_user_.default default

Now type exit and remove the CD. Boot normally into Windows and you must be back to normal.