One time, upon rebooting the system, I got this message:
BOOTMGR is missingI rebooted from the Windows 7 DVD and went to the "Repair your computer" option. It said "Searching for Windows installations." Then it showed me the System Recovery Options dialog, listing "Windows 7 Ultimate (recovered)."
Press Ctrl+Alt+Del to restart
But that's not what it showed me the first time. The first time, it showed me nothing. I read somewhere that somebody found that they needed to run the Repair Your Computer option a couple of times before it would work, so possibly that was what finally populated this dialog with a Windows 7 entry. But what I think may have solved the problem was that I booted with an Ubuntu 10.10 Live CD, went into System > Administration > GParted, and used their filesystem repair option (or whatever it was called, exactly) on my Windows 7 partition. (I'm not sure if GParted is included in more recent versions. If not, the 10.04 version will still be available for a while.)
Anyway, I did now see Windows 7 Ultimate (recovered). I clicked Next > Startup Repair. It said "Searching for problems" and then "Attempting repairs." Then it said, "Restart your computer to complete the repairs." I did that. The problem was solved.