Whenever you install a new Windows OS with dual boot on a previous Windows OS then the multiboot menu automatically appears on startup. So if you install Windows 7 as a second operating system on a PC where Windows XP is already installed, the Windows boot menu incorporates the options from the older boot menu.
But now considering the reverse scenario, you are having Windows 7 installed and then you tried to install Windows XP on dual boot. After the installation is complete then Windows 7 is no more running although it is intact and in working condition. What actually happened is that you have overwritten the MBR with the older version of Windows which can’t recognize Windows 7 bootloader.
But don’t worry it is very easy to restore the bootloader. Just follow these steps:
- Start Windows XP and insert Windows 7 DVD.
- Browse the disc(I am assuming “G:” as the drive letter of your DVD Drive)
- Open command prompt with elevation(By right clicking cmd.exe and selecting “Run As Administrator“)
- Navigate to folder “G:\boot” in the elevated command prompt.
- Type “bootsect.exe /nt60 all” at the prompt.
- When you restart now you will have Windows 7 back but soon you will realize that XP has gone. Nothing to worry we have to just add the entry of XP bootloader.
- Start windows 7 now and again open elevated command prompt.
- Write bcdedit /create {ntldr} –d “XP Menu Text” on the command prompt and hit enter. BCDEDIT is the boot configuration data editor for Windows Vista and 7. You can invoke this command from any path on command prompt. In the above command “XP Menu Text” is the text which will appear for the entry of XP at startup in the multiboot menu. You can change it to anything more descriptive.
- Now just restart.
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