"data primary hard disk drive 0 failure" message

Hi everyone, my PC was doing the blue screen of death with this code 0x000000ED so I tried to restart it in safe mode using the F8 key. This didn't work and I then used F2 in setup utility and ran diagnostics using F12. I then got this message: - 

Hard drive diagnostics running. Please wait…

Drive 0; error attempting diagnostics

Drive 1; no device

Drive 2; HL-DT-STDVDRRW GWA-4083B-diagnostics not supported

Drive 3; no device

Now the message that comes up when I try to boot is "data primary hard disk drive 0 failure" - I already tried to remove my hard drive and put it back in again, trying to make sure everything was connected properly but this hasn't made a difference.

Can anybody help? It's an old computer but I really just want to get all my data off it and save it to a new one.

Thanks!