It's hard to say what the continuous beep is without knowing your motherboard. Each board uses a different BIOS and each BIOS (Phoenix, Award, etc..) has different beep codes for different conditions. That said, usually when I've encountered a continuous beep it's because the memory isn't in tight, the memory is faulty, or the graphics card isn't seated correctly. Go to the motherboard's website, find out what kind of BIOS you have, then google that BIOS's beep codes (like "award bios beep codes") and you'll usually get a nice list. This is a site I usually refer to:http://www.computerhope.com/beep.htm
Of course, the only one listed on here with a continuous long beep is an IBM board and I'm quite confident you don't have one of those, so I'd check the memory and graphics card first.