Cannot Find Windows XP Operating System
If you cannot find the Windows XP operating system when you set up multi boot Windows 7 or multi boot Windows Vista, this is because of the new boot loader in Vista and its successor, Windows 7. The concept of multi boot was made possible from Windows 98SE forward. Before the release of Windows 98, you could have only two operating systems on your computer. With Windows XP, Microsoft introduced a new boot loader (NT Boot Loader, called NTLDR for short). It allows you to setup multiple operating systems on a single computer. Windows 2000 and Windows NT also carry the same NTLDR.
The rule of the thumb is to install the latest operating system first and then its immediate predecessor. For example, you would load Windows XP, then Windows ME, and then Windows 98SE. This makes it easy for the boot loader to understand that you installed another operating system. While it was easy with Windows XP, you cannot expect the same with Windows Vista and Windows 7. As soon as you install Windows Vista to set up a dual boot Windows Vista, your boot loader will stop recognizing Windows XP. There is the same problem when you set up a multi boot Windows 7. As soon as you install Windows 7, you cannot find the Windows XP operating system.
Even though you are following the rule of installing Windows 7 first and then Windows XP, you may not find the latter. The reason for this behavior is that the boot loader of Windows Vista is different from that of Windows XP. It would not recognize Windows XP. As Windows 7 is just a good enhancement of Windows Vista, or rather, a combination of Windows Vista and Windows NT 5.5, it employs the boot loader of Windows Vista. This is the reason why you cannot find Windows XP operating system even when you setup multi boot Windows 7 or multi boot Vista.
The following section gives you a simple solution when you are unable to find Windows XP after installing Windows 7 or Vista.