Repairing Windows 7 installation using DISM after motherboard replacement

I have a Dell Dimension 9200 (bought in 2006) with Windows 7 and Windows XP MCE 2005 loaded on it. Though Windows XP MCE 2005 was doing ok, Windows 7 was struggling to get off its foot due to inadequate processing power. Eventually I decided to replace it with a new home built system. For that I went with a motherboard (ASUS Z87 Plus) which supported Windows 8 and the latest Intel Haswell processor. I had a plan to reuse the old hard disk with Windows XP MCE 2005 and Windows 7 on it. Little did I realise that building a new system with an old hard disk with OSes wouldn't work straight off. I desperately needed Windows 7 to work to take advantage of upgrading to Windows 8 and thereafter to Windows 8.1. Though I was distraught in the beginning, I found a way of getting Windows 7 to work within the new built system using the DISM (Deployment Image Service and Management) tool within the Windows 7 installation disk.  

This is how to do it with the courtesy of the article I found on the web.

1. Load the original DVD with Motherboard drivers for Windows 7 into the DVD drive bay. If you don't have the drivers, you can get it off the Motherboard manufacturer's website. Just load the drivers onto a USB memory stick and put it into a USB slot of the PC. You can also burn it onto a CD or a DVD,
2. Load the original Windows 7 installation DVD into the second DVD drive bay. If you have just one DVD/CD drive bay, you are better off copying the Motherboard drivers onto a USB memory stick,
3. Boot the system off the Windows 7 DVD,
4. Go into Repair your Computer,
5. In the Recovery console, go to Command Prompt.
6. Identify the drive letter of your CD/DVD drive or your USB memory stick. In my case it was I:
7. Next, identify the drive letter of your Windows 7 installation on the hard disk. In my case, it was G: 
8. Type the following command, dism /image:G:\ /add-driver /Driver:I:\ /recurse. 
9. You will notice that the drivers being installed on your Windows 7 drive. Be patient as not only the Chipset drivers, but also the LAN, Audio and VGA drivers will be installed.
10. Once all the drivers are installed, restart the machine. 

There you have the system with Windows 7 working all over again.

However, I will not be able to get back Windows XP the same way. The reason being Intel's Haswell processor doesn't support Windows XP.