Hi, different models of computers use different short keys to access BIOS and boot order.
Are you talking about the boot order, which helps you choose where to start the boot from, or is it a blue screen (this is called the BIOS page).
Is there some way to restart everything from there without the cd?
I'm sorry, nothing in my knowledge. There may be ways.
Reformatting is the best option.
If you do not know how to do that, you'll have to ask an expert/professional.
Since this is a Dell computer, you can ask them for a service, but you will have to pay, because I think you've run out of the free service period.
The other option is to buy a hard disk enclosure and converting the internal hard drive to an external one and then reformatting it.
Or you can order for a XP CD online from Microsoft
here