Good people please help I am trying to format my PC then I am getting this error "BOOTMGR is missing", what might be the problem???The message means that your boot device does not have all of the software needed to start the system.

This message is rare on a new computer. If it is very new, talk to the vendor or the maker of the computer.

Please provide more information.
Is this a computer? A laptop? NET book?
What brand and model?
Did it work OK a few days ago?
What changes were made to it?

Do you know the NAME of the OPERATING System?

There is a method for fixing this in WINDOWS 7, but before giving your the instructions on this, it would be better if you check for anything that has changed non  your computer. Do you know how to start the BIOS and check for the list of boot devices?

The computer is very old, when formatting with windows 7 it will load windows files for some few minutes and pop out a blue screen saying I must off and disable bios...etc

Please help me how to disable the bios and restart them Let's start at the top. If the computer is very old it's very LIKELY it will not support Windows 7. First thing you need to do is run the hardware compatibility applet AND make sure there are W7 drivers available for all installed hardware.