What to do when hard disk have bad sectors

I district my 80GB hard drive into C, D, E, F 4 partitions, the recent when boot, the system self-test and prompt "Warning: Immediately back-up your date and replace your hard disk drive, a failure may be imminent". Sometimes i press the Enter key to start normally, there have been crash phenomenon that unable to enter the system. Many times I have to format the partition and reinstall the system, but still have the failures, how to solve it?

When computer self test and prompt the above information that means "immediately back up the data stored in the hard drive and replace your computer's hard drive, a failure will soon occur." At this point you should do the following:
(1) use the disk repair software (such as PQMagic) check the hard disk under DOS mode, if the data damaged (such as navigation records are missing) and other soft fault, you can repair it directly, if hard disk have bad sectors such as hardware failure, you can use hard disk repair software to repair bad sectors or temporarily isolated it.
(2) then re-partition and format the hard drive and reinstall the operating system operation.
(3) If the disk has bad sectors, re-partition approach to isolate bad sectors are only temporary treatment measures, you should send your hard drive to the professional hard disk maintenance department to repair.(Prior to this, please backup of important data to prevent loss).