SVCHOST.exe and IDE Device Error. How do I fix this?

Hi, I've got a Dell Inspiron 1520 laptop running on Windows XP. Recently, when I tried to turn on my computer, everything seemed to run normally until I got to my desktop screen. I could see my familiar Avenged Sevenfold wallpaper, but my icons weren't coming up. I figured it was just going a little slow, so I waited. A window appeared and said there was an error with the scvhost.exe and prompted me to press OK to continue what I was doing or Cancel to 'debug'. I pressed Cancel and a blue screen came up (I couldn't read it, because just as quickly as it appeared, it disappeared) and then my system restarted itself. I ran a diagnostic and the S.M.A.R.T long self-test failed and said that the IDE Device had failed. I don't really know what that means... I attempted to go through Dell Support, but I was placed on hold for nearly an hour and my problem was not tended to, as they seemed more interested in having me buy software and accessories than listening to the issue and helping me fix the problem (not to mention, the one gentleman I spoke to was quite rude). So, if anyone has any suggestions as to how I might repair this myself, please enlighten me. Your istance is appreciated. Thank you.