Situation: Quite some time ago I was running Windows XP, and I installed Windows 7 on a separate partition in case I had to go back. I finally decided to repurpose the old Windows XP partition, and was tired of being asked to select an OS every time my computer booted, so I switched the "Active" partition to the Windows 7 partition. Disk Manager displayed a message along the lines of, "Make sure this partition has an operating system installed, or else your computer won't boot!" Of course, it does have an OS installed, but my computer won't boot - I'm getting a "BOOTMGR is missing" message.
I booted my computer from a Linux disc to switch the system partition back. What I want to know is:
- Why was my Windows 7 partition not bootable? Shouldn't the Windows 7 installer have made that partition bootable?
- What could I have done ahead of time to detect that this would happen, and to prevent it?
- How can I get the Windows 7 partition to boot, so I can wipe the old XP partition entirely?