Incorrect capacity

There are some reasons why you get a less capacity than actual:

  • Virus attack: using antivirus software to remove viruses.
  • Not a genuine Cruzer USB drive.
  • Format with an improper format tool: you can format the 128GB hard drive to NTFS or convert USB to NTFS without losing data, then resize it to its actual capacity.

Just troubleshoot the problem, then try to fix it.