You can install Windows XP in dual-boot configuration with an existing Windows NT based operating system. Such installation allows you to choose either of the operating systems while starting the computer system. At times, when Windows XP is configured for dual-boot, it might fail to start displaying an error on screen. This might occur if the existing Windows operating system has replaced the boot files of Windows XP, thereby has resulted into an unbootable system. You might need to use your backup to restore the data thus lost. But if no valid backup is available that could give the desired results, you will need to use powerful data recovery software.

For an instance, you are using Windows XP that is configured in dual-boot configuration. You might receive the below error message when trying to boot your Windows XP installation:

"Windows XP could not start because the following files were missing or corrupted:
WINDOWS\SYSTEM32\CONFIG\SYSTEM NTLDR MISSING
You can try to repair this file by starting the Windows Setup program from original floppies or boot from CD-ROM.
Select 'r' at first screen to repair"

You cannot access the data that is stored in Windows XP installation.

Cause

As the error suggests, it occurs when system fails to access Windows XP boot files: Ntldr and Ntdetect.com. This usually occurs when you are using Windows NT 4.0 with Windows XP and Windows NT 4.0 has replaced the shared boot files since it doesn't recognize Windows XP startup features. Such behavior might result if any of the below conditions is true:

You have installed Windows XP before installing Windows NT 4.0
You have recently reinstalled Windows NT 4.0

Solution

To solve the problem, described above, you need to replace the corrupt Ntldr and Ntdetect.com files by following these steps:

Boot the system from Windows XP installation disk and start Recovery Console
Use fixboot command at the prompt and then press ENTER
If the above measures fail to work, reformat the drive and reinstall Windows XP. Restore lost data from backup thereafter.

You need to use data recovery tools to successfully recover lost data if backup is absent or is not valid. Data Recovery Software are advanced applications designed to recover lost data while any condition of logical data loss.

Stellar Phoenix Windows Data Recovery is a fully-featured recovery application designed for Windows 7 RC1, Vista, XP, 2003 and 2000 based system. It is a non-destructive Data Recovery Software to support recovery from all hard drives, CDs, USB drives and more. It supports FAT32, VFAT, NTFS and NTFS5 file system drives.