Are you saying that you have a hard drive with bad sectors?
If so, how did you come to this conclusion?
If you want to find out if a drive has bad sectors, or just to run a hard drive health check, use UBCD
I use that tool all the time, it can check hard drives, check for and delete viruses, ghost hard drive images, and so much more.
You have to custom build and burn your own boot cd, but once you do, you will find that UBCD is an invaluable tool. They update it all the time to keep up with the latest viruses and other tools to use.
If you don't want to go through all that, tell us what hard drive it is you are having issues with (if that is the case) and we can tell you where to get the program to put onto a cd or floppy disc to boot from, and run checks on the disc.
I suggest doing this instead of using checkdisk in windows, as it is not as thourough. An actual hard drive utility program gives you more data, and a better idea what the condition of the disk is.