Four ways to reinstall Windows when upgrading/changing the motherboard

Option 1:

Run SysPrep.  Here's how to use it.  Make sure to get the correct version of SysPrep... each version is unique to Window's Service Pack level.  The SysPrep for Windows XP is different than the one for Windows XP SP1, or SP2, or SP3.  Click here to search the Microsoft Download Center for "sysprep".  I prefer the Reseal option myself; this forces you to reenter your CD key, give your computer a name, and then runs the hardware detection portion of setup.  Although this is a very clean way of doing this, if you don't HAVE your CD key handy then use...

Option 2:

Use a Windows CD and boot into the Recovery Mode Console. There you type in fixboot (this will replace the HAL so Windows can now interact with your new hardware), type fixmbr (this will create a new MBR entry), and then type exit (this will reboot your computer), eject the CD and you should be able to boot into Windows. There all you need to do is install the new drivers and it will be fully functional. You may have to call up Microsoft to reactivate your version of XP because you now have different hardware hash number, but...

Option 3:

Windows Reinstall may also work.  Or...

Option 4:

Before you swap out hardware, boot in to Windows one last time, Regedit, and under "HKEY_Local_Machine" then under "SYSTEM", under EACH "ControlSet" folder (you could have several), delete the "ENUM" folders.

Need a boot disc?  Check out the Mick's Old-Fashion Boot Disk Creator or www.bootdisk.com.