Help with old POS "Compaq Deskpro 2000"

[Asimov]

I recently got an old Compaq machine. Since it had a weird bios and I couldnt get it to boot from floopy I decided I would take out the HDD, stick it in my own machine and format from windows.

The problem is that when I stick it back in the Compaq I get this error, as I should, telling me to remove all non-system disks or some similar crap just as if there is no OS.

Of course immediately after I realised this was a bad idea because I still cant get into the bios to change the boot settings.

Then I decided to copy the content from a pre-install of windows to the newly formatted harddrive. No luck, same results.

Its really starting to $hit me off. Help would be greatly appreciated. As I've really got no clue...