Recently got an old dell dimension e521. Had plans to use it as a media computer, so I threw a nice sound card I had and an SD card reader for fun. It also needed a drive, so I threw a 250 gig hard drive because I didn't need much space. Now whenever I boot it gives off one long beep and then a continuous loop of shorter beeps. Scoured the internet for answers, and it did not provide. Would appreciate some help with someone who knows dell post codes.