Hello: there are a number of possible causes for "BOOTMGR
is missing" error message.The most common reasons for BOOTMGR
errors include corrupt and mis configured files, hard drive and
operating system upgrade issues, corrupt hard drives, an outdated
BIOS, and damaged or loose cables.First we are going to try the start
up repair.You will need your windows installation disk or recovery
disk.Put it on your cd rom,restart and watch for a Press any key to
boot from CD or DVD...Press a key to force the computer to boot from
dvd.Once it finished loading files Choose the Language to install, Time
and currency format, and Keyboard or input method that you'd like to
use in Windows Vista.Click on the Repair your computer link on the
bottom-left of the Install Windows window.This link will begin the
Windows Vista System Recovery Options.Wait a minute to search for
your hard drives.
Choose the Windows Vista installation that you'd like to perform the
Startup Repair on.
Click the Next button.
The Startup Repair tool will now search for problems with important Windows
Vista files and try to repair them.Your computer may or may not restart
several times during this repair process. Do not boot from the Windows Vista
DVD on any restart
Click the Finish button once you see the Restart your computer to complete
the repairs window to restart your PC and start Windows Vista normally.
Now your done and is supposed to work normally.