Install a new motherboard, without changing your old OS.

Have you ever tried changing your motherboard while keeping all the remaining components
constant, including the operating system.  Chances are that you will be greeted with a
BSOD (Blue Screen of Death) the moment you boot the machine. So what are you supposed
to do of you want to install new hardware, including your motherboard while retaining the
old OS on your hard disk.

Here is a trick that will allow you to install new hardware without the need to reinstall Windows.
Windows XP repair install is the trick.  By doing this, all your hardware will be re-detected and
the necessary system files will be automatically reinstalled without affecting the registry or
the user data residing on the system.  Hare’s how you do it.

Insert the Windows XP CD and restart the PC.

Now select the ‘Press enter to set up Windows XP now’ option.

To skip the EULA, press [F8] and  finally press[R] to begin a repair installation.

Now the XP installation process will begin but none of your old data will be replaced
or deleted.

Re-active Windows and you are done.