hey guys, can someone help me with my computer problem please?

It’s a hand-me-down, Gateway computer, Windows 7.  I booted up yesterday, and it has a black screen on startup and the only text that shows is "Press F2 to enter startup." 

I press F2…and then, it says Please wait… and nothing happens.  I let it run, and eventually the computer goes to sleep. :-/ 

I did a little research, and it said the battery in the motherboard could be the issue.  I tested it, and it has a full charge.  I’m not finding much else that is helpful for troubleshooting.

Any other ideas?