Most painless way to restore Windows 7 bootloader?

I believe EasyBCD can do this, but to do it manually you can do the following:

  1. Copy bootmgr to the root of your volume (probably C:\).
  2. Run bootsect /nt60 /mbr /sys (I hope I got the command-line right)

I'm not sure where I found bootsect -- it might have been in C:\Boot, or it might have been in the Windows AIK or on the Windows CD. You'll have to search for it.