HOw to maintain my harddisk drive from bad sector?

There isn't really a method of preventing bad sectors on a disk.  Bad
sectors are generally caused by physical damage to the disk, making
that sector unreadable.

The best thing to do is use a software utility, such as Norton Disk
Doctor, to routinely scan your hard drive and mark the bad sectors so
your computer will not continue to use that area of the disk. 
Microsoft Window's Scandisk also provides some support for marking bad
sectors.

Many drive manufacturers have their own tools as well.  For example,
Western Digital provides Data Lifeguard and Quantum provides PowerMax.

If your hard drive starts to develop bad sectors, I would immediately
back up everything of importance and then look at replacing the drive
with a new one.

Hi oemar-ga

HOw to maintain my harddisk drive from bad sector?

- Keep your PC clean and lovingly.
- avoid improper shutdowns
- i hope you have a UPS installed to keep away all spikes(a transient
variation in voltage or current) and regulate the voltage reaching
your PC.
- Scandisk and Defrag in regularly... once a week. (atleast once a month)
- if your harddisk has already gone bad.. you can go for Low level
formatting and reuse. (if sector 0 is not affected)

Regards.
*yd*