My old Dell computer is being very strange. The hard drive recently failed. Now it is replaced. But now, I get it beeping at me 6 times. Nothing is on the screen, so I'm assuming it's the BIOS complaining about something.. but what is it complaining about? It's definitely not the hard drive because I unplugged it and it still beeped. I pulled out all of the USB things and it still beeped. What is wrong?