Fixing "BOOTMGR is missing"Error While Trying to BootWindows 7 or Vista

If your Windows 7 or Vista computer has
encountered the dreaded “BOOTMGR is
missing” error, you aren’t alone. If the
problem isn’t hardware related you can fix it
with relative ease as long as you have a
Windows DVD handy.
If you don’t have one, you can create a
Windows Vista repair disk using our guide.
Boot off the Windows Vista DVD and then
click Next at the first prompt:
You should see a link in the lower left-hand
side for “Repair your computer”
The installation process will attempt to find
your Vista installation directory. If there’s
more than one in the list, select the correct
one and then use the Next button again.
Click the first link for “Startup Repair”
The installation process will repair the system,
and then prompt for you to reboot.
Alternatively you could have chosen the
Command Prompt option instead, and use
the following command to fix the boot
options only:
bootrec /fixboot
At this point you should be able to reboot your
computer, remove the DVD and everything
should be working.