A dual boot computer has two operating systems installed on it. Typically, people install two versions of Windows on the same computer. As the computer boots up, it gives you options to choose one of the operating systems. If you install Windows XP first and then Windows Vista, 7 or 8 then everything goes okay. But if you install Windows XP after installing any of the later versions of Windows, then you can boot only in Windows XP. You can fix this by using a free tool called Dual Boot Repair Utility.
The Dual Boot Repair utility comes with Visual BCD software. So you have to download and install Visual BCD on your system. You can download Visual BCD from Boyans website. After the installation, you can run the Dual Boot Repair Utility from the Start Menu. It has a very simple to follow interface.
There are many options like repair BCD, backup or restore BCD. You have to click on the green colored Automatic Repair button to start the automatic repairing of your dual boot system. It would display a information message box telling you what it is going to do if you proceed. On my Windows 7 + Windows 8 dual boot system, it displayed that automatic repair is possible and Windows 7 would boot by default in the dual boot mode.
Now all you have to do is click on the OK button to proceed with the dual boot repair. This would fix the settings in your BCD store and after that you would have to reboot your PC. At the next boot, you would be able to find the new fixed dual boot menu.
So if you are having problems with dual booting and are unable to boot into the newer versions of Windows after installing Windows XP, then you should download and use Dual Boot Repair Utility to automatically repair your boot menu.
You can download Visual BCD / Dual Boot Repair Utility from http://www.boyans.net/.