This guide tells you ‘How to dual boot Windows 7 and Windows XP’ with Windows 7 installed first. This case is applicable for users who have Windows 7 pre-installed on ‘C’ and want to install XP on their ‘D’ partition.
The process for this is same as we did for Windows XP & Vista. Follow the simple steps below to install XP after Windows 7.
1) Make a clean Install of Windows XP on ‘D’ partition of your hard drive. Assuming, Windows 7 is installed on ‘C’ partition.
2) After restarting system, you will directly boot into Windows XP. That’s because XP writes its bootloader over Windows 7. So, we need to restore the Win 7 bootloader.
3) To restore 7, you need to Boot from the Windows 7 DVD and “Repair your computer”. Check this article “How to Perform a Startup Repair in Windows 7” to perform repair.
4) After repairing, your system will restart and boot into Windows 7.
5) Download and Install EasyBCD on your Windows 7 to add boot entry for XP.
6) Launch the program and select ‘Add New Entry’. Under “Operating Systems” open the Windows tab, select the Type as “Windows NT/2k/XP/2k3” and click on ‘Add Entry’.
The entry for Windows XP would be added instantly. You can choose the default OS to boot and modify the boot menu time-out from “Edit Boot Menu” option.
That’s it. Now restart you PC and you’ll be presented with two options, Windows 7 andWindows XP. 
