Write MBR Code

Question

I am an electrical engineer who has recently discovered the need to modify the code in the MBR. Basically I need the ability to execute code on the HDD before, the OS starts up

Answer 1

I found a similar question which may help:

Modifying the MBR of Windows

However, you may want to elaborate on what you plan to do. As I have found out myself bootloader code can be quite tedious to work with. Also, I would certainly test this with a floppy if possible.

As far as actually doing this all from Windows, I am a bit clueless. Just about all of my programming experience to this point has been under a Unix environment.