Dell Inspiron 1501: help needed!

When I start up my Dell Inspiron laptop, I get a black screen with an error message: "Windows detected a hard disk problem. Back up your files immediately to prevent information loss and then contact the computer manufacturer to determine if you need to repair or replace the disk." I could however still start Windows. I later got the error message: “SMART Failure Predicted on Hard Disk 4

WARNING: Immediately back-up your data and replace your hard disk drive. A failure may be imminent.

Press F1 to continue. 

I pressed F1 as it told me to and all I'm still getting is a black screen with a white cursor in left corner. I could no longer start Windows.

I've tried many options, including putting in the Vista installation disk in and trying the tools on that except install the OS, I don't want to lose my data if at all possible. Unfortunately none of the options or so called solutions worked. If you know of any possible solutions, please comment below. 

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