1. Find a Win98 boot disk. Stick it in the A: drive and start your machine.
2. Once fully started, run FDisk, delete ALL logical and primary drives.
3. Create a primary drive, then any logical drives you may want.
4. FDisk will then verify integrity of the drives AND locate/mark bad sectors on the disk.
5. Once, FDisk has finished, Exit FDisk and run Format C: (and any logical partitions you may have created).
6. Reboot and setup Windows from CD.
I use this method because recently I've installed Windows about 4 times, and within a week of each install, my pc became unbootable. After each install I ran scandisk/chkdsk but could not find anything wrong so I thought my sister messed around with the machine. But this was not the case because I finally decided to use FDisk which found bad sectors on the disk. Windows chkdsk/scandisk never found/fixed the errors.