USB drive showing half capacity?

The other day something weird happened to my USB drive.

Here’s my story…

I have a capacious 64GB USB Drive.

It’s like sitting first class on Delta Airlines, sitting in the handicap bathroom stall at Old Navy or sitting in the front seat of a Hyundai Equus.

It’s big.

I purchased this thing when 64GB USB drives began flaunting their commodious features – so it wasn’t cheap.  And I’m proud of the space.So, I wanted to install Mac OS X Yosemite in VirtualBox so I installed IESD, converted the .app to a .dmg and ran HDITUTIL to spruce up final product.

Once I finished my digital hocuspocus, I plugged my thumb drive into my Mac Mini but when I dropped the 32GB file onto the drive, my Mac bitched about there not being enough space on the destination drive.

I had to do a double take.  I knew my USB drive wasn’t damaged because it was just working a moment ago.

Low and behold, when I pressed Command + i and viewed the info, my Mac was only detecting 32GB of space.  In fact, it erroneously thought the maximum capacity of my 64GB drive was only 32GB.

Let’s just say I was bit peeved.

Flustered, I yanked the drive and roughly attached it to my PC.

Perhaps it’s a Mac thing right?

But Windows was showing the same problem.  I thought about reformating the volume; however, 32GB was the largest capacity visible from the drop down list.

I didn’t even have an option to format at 64GB!

What the heck are you supposed to do when the Windows format tool won’t let you format your removable media at full capacity?

Diskpart will save your butt man

This is seriously a task for diskpart.exe.

It’s a built in Windows tool that lets you partition your disk.  In other words, it lets you divide up a physical disk into logical volumes.  You can also delete partitions.

It’s this last part, deleting partition, which saved my butt.

Here’s how this works:

Bust open a command prompt and type diskpart.  You can get here fast by pressing the Windows Logo key on your keyboard and the letters “xa”.

The first thing we need to do is list all the disks that Windows knows about.

Type:

list disk

From the graphic above, you can see diskpart knows my disk is 59GB.  So that’s a good sign.  It’s not showing up in the GUI though so we need to fix that.

Let’s select the disk number that represents our USB drive (just substitute the disk number with the respective one showing up on your screen):

select disk 1

and then select the partition. We want to select Partition 1 because it’s the only partition on the USB drive and we need to nuke it.

select partition 1

Now we need to delete this partition.

Now this part is crucial.

Make sure you are 100% certain you selected the right disk because there is no way to back out of this process.  Once we type delete partition all the data will instantly be obliterated.  There’s no confirmation or warning box.

Scary but true.

delete partition
Now we’ll create a shiny new full-size partition.

create partition primary

Great, now type:

list partition

We want to make sure that everything looks good.  You should see Partition 1 with the correct size under the Size column.

Now type exit to get out of diskpart because our dirty work is done!

If you right click your USB drive in File Explorer and choose format you’ll see the full capacity listed.  What a welcome change.

And that my friends is how to make your USB drive show full capacity again.

Yeah!