Can't fully clean hard drive

[shutteringfocus]

I have a 320 gb hard drive that used to be inside a laptop. I'm trying to fully format it and erase everything so I can put it into my desktop as an extra drive.

I can only free up 298.09 gb on the disk. There must still be some Windows 7 system files or something on there that wont go away.

If I right click the drive in Disk Management I cannot convert it to a dynamic disk.

What do I need to do to wipe this drive completely and get all 320 gb back?

 

[derekimo]

Sounds like the right actual size to me,

This may help or confuse, roughly though the actual size is about 93% of advertised size.

"320 GB" hard drive = 320,000,000,000 bytes / 2^30 bytes in a gigabyte = 298.02 GB

http://www.sevenforums.com/hardware-devices/23890-hdd-s-advertized-size-vs-actual-size.html