computer wizardry

having successfully sorted out my dad's Internet connection I returned home to find that my computer was behaving very strangely.
It wouldn't start up and just kept reverting to the BIOS screen.
I spend ages trying all sorts of codes and tricks but it seemed that I was going to have to leave it until I could afford professional help.

Then I spotted it.......

......a crumb jammed down the side of the delete key!