I turned on one of my PCs the other day after plugging in another drive to check it. Obviously something went amiss as it would not boot up.

I was getting a msg ‘BOOTMGR is missing. Press Ctrl+Alt+Del to restart’.

WTF?

Looks like the Master Boot Record (MBR) had become corrupt. Fortunately there was an easy fix for this:

Disclaimer: Proceed at your own risk. I take no responsibility for any loss of data caused by the actions below.

* Find your Windows CD and boot off this (as if you were to reinstall)
* Enter recovery mode (Option R from the main screen)
* You will be prompted for the admin password. Enter it.
* Type in ‘fixboot’
* Type in ‘fixmbr’
* Type in ‘exit’

The PC should now boot and startup as per normal.

Good Luck!