How To Recover Unallocated Space on a USB Flash Drive

This article describes how to Recover Unallocated Space on a USB Flash Drive (or USB Thumbdrive).

Problem

You have a "large" USB Thumbdrive (say 16GB). You've done something that results in it appearing to have only 6GB of space.

Backup any data you want from you Thumbdrive
Open up a Command Prompt by going to the Start Menu and typing "cmd" in the search box at the bottom
Type "diskpart" to start Microsoft DiskPart (which is a Disk Partitioning Tool)
Type "list disk" to show a list of disks connected to your computer
Type "select disk <#>" (ie: "select disk 6") where <#> is the number of your Thumbdrive. You should be able to get an idea of which disk is the correct on by the Size. If you still aren't sure follow the substeps below
1. Open the Start Menu
2. Right-click on Computer and choose Manage
3. Click Disk Management from the left column
4. Click you Thumbdrive in the top center window. The bottom center window should go the associated entry which lists a Disk #
Type "clean" to remove all partition information
Type "create partition primary" to build a single partition that covers all available space