Formatting the hard disk several times smaller?

Users questions:I use ntfs format c disk, formatted c drive after a few smaller, and was originally 9g, has now become 4.5g, and how to solve this problem? System in the c drive, I also do not understand, do not know how to make it clear that if the re-partition the entire hard drive data that no effect? I do not want to format the entire hardDisk has bad sectors
Experts answer:
  • This information provided by the users.Thanks!