I was having problem regarding storage amount shown in my 16GB pen drive as 2.2MB only. Means it wasnt cleaned completely. So i found the following DOS commands to clean the drive you want. It worked beautifully and now, problem is solved.
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DISKPART> list disk
Disk ### Status Size Free Dyn Gpt
-------- ------------- ------- ------- --- ---
Disk 0 Online 298 GB 0 B
Disk 1 Online 7509 MB 6619 MB
DISKPART> select disk 1
Disk 1 is now the selected disk.
DISKPART> clean
DiskPart succeeded in cleaning the disk.
DISKPART> create partition primary
DiskPart succeeded in creating the specified partition.
DISKPART> exit
- Open cmd and type DISKPART.
- A new promt box will get open and then start typing the following commands.
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DISKPART> list disk
Disk ### Status Size Free Dyn Gpt
-------- ------------- ------- ------- --- ---
Disk 0 Online 298 GB 0 B
Disk 1 Online 7509 MB 6619 MB
DISKPART> select disk 1
Disk 1 is now the selected disk.
DISKPART> clean
DiskPart succeeded in cleaning the disk.
DISKPART> create partition primary
DiskPart succeeded in creating the specified partition.
DISKPART> exit