Why does 500 GB HDD show as 1000GB in Disk Management?

Question

I am using a Western Digital 500 GB HDD. But when I open Disk Management in my system it shows:

Disk 0
Basic
826.12 GB
Online

When comes to partitions it is showing 361 GB of unallocated space in black color with my regular 500 GB partitions. There is also a 50 GB partition which I can't access.

Answer 1

It is very rare for hard drives to wrongly report their size (as opposed to flash drives), and it may well be that you do in fact have a 1TB drive that the manufacturer for some reason chose to only allocate 500GB for use.

As you have already found the disk management console you can do one of two things, you can create a new partition on that drive (right click the empty space then select "New Partition") and then test that space to make sure that you can safely store data on it, or you can simply right-click your existing partition and (on Vista and Win7 at least) you will have an option to extend that partition to use the remaining space.

Answer 2

Are you sure you didn't buy a 1TB drive? 920GB usable space for that size is about right after overhead and windows formatting, as 1TB is actually 931GB usable.

You don't say if it is an internal or external drive, but Western Digital drives usually come in the WD500 or WD100 format, so check the drive's ID and let us know.