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I currently dual boot Windows 7 and XP. I know XP was installed first, and then at some point, I added a hard drive with Windows 7. I used EasyBCD from Windows 7 to setup the bootloader.

Now, I would like to reformat the XP drive (and use it for media storage), and use Windows 7 only. However, I'm worried that I might lose the master boot record (MBR) or not be able to boot into Windows 7.

Is there a way to know which drive stores the MBR? I'm not even sure I understand exactly how the MBR manages two OSes, or if each drive gets an MBR, or if that makes a difference in this case. Anything that could help save me a headache down the road would be helpful.

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Pull out the drive with Windows XP on it and if you computer still boots you can just format that drive from within Windows 7 worry free. :) If you mess up your bootloader the Windows 7 install disk can repair it fairly easily.

If you pull out the XP drive and the system will not boot you can try to repair the bootloader with the Windows 7 DVD and then you should be set to reformat the XP drive.

If you installed that Windows 7 on another machine and pulled the drive then plugged it into the current machine... and it booted to Windows 7 not asking about XP then both drives should have there own MBR for booting it would be that you had the Windows 7 drive set to boot first.

You said you used EasyBCD not sure what it does but it may have just added an entry into the bootloader to allow you to select the secondary drive to boot. If you format that XP drive you would still have the XP boot entry and would need to remove it using EasyBCD or another method.

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That's good advice. I'll try to unplug the XP drive and see what happens. Hopefully no problems! – Ishmael Smyrnow Apr 22 '11 at 0:27
Okay, so unplugging the XP drive kept me from booting into windows. Using the Windows 7 Repair disc, I did a startup repair. It said that I didn't have a system partition on the drive, and fixed the problem automatically. It then rebooted and sent me straight into Windows 7. – Ishmael Smyrnow Apr 22 '11 at 16:32

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