Is hard disk damage?

When I turn on computer, maybe last time shut down computer not propriety so computer scandisk frist but it take me a lot time, so I select exit But after PNP Init completed
why got warning display.
Smart Failure predicted on primary master:Maxtor5T020H0 (I install 2 hard disk)
Warning: Immediately back-up your data and replace your hard disk drive. A failure may be imminent.

Windows can log on(must select),I defragment the C:/ drive, also scandisk again in dos. But can’t solve the problem.

What shall I do? I dun want see the warning and is hard disk damage?

Thanks!