Dell Dimension 4100 start up problems

I turn it on and get the Dell logo for 20 sec., then goes to a black screen with system info. At bottom, it says Press <Del> to set up.
When I did that it looped back to the Dell logo, and then to the black screen again.
I changed the battery, optimistically.
Now, when I follow command to press Del, I get the Set up menu, with Main, Advanced, Security, Bot, Exit on the top.
I have no idea where to go from here and would appreciate some help.
Thanks, Geek-gods!

 

I assume when you press Del, it is taking you to the BIOS from your description.
What happens when you press F10 to exit?

 

Nothing happens. The black screen with the blue Dell icon and system info remains.