Windows XP SP2 System error

Hello,
When i turn on my computer the dell loading screen pops up and the loading bar fills up then i get a black screen that says "loading PBR for descriptor 2. . .done" then i get a message saying "a disk read error occurred" I did a little trouble shooting myself and it seems that my computer isn't finding my main hard drive. i tried to run my computer using the XP start up disk and use the Recovery console but it seems like it can't find my hard drive because it doesn't do anything.