Hard Drive Space Query

[Buff]

Hi,

I'm bit of a novice with hard drives/computers, and there is probably a simple explanation to the following (I hope!), so wondered if someone could help me out?

I'm just wondering why the used space on my hard drive(s) is a lot more than the total of the individual items?

For example, my main hard disk is published as a 250GB drive - it is partioned into two drives, the C drive and the E drive; the latter is labelled Recovery. The E drive is 10GB and the C drive is 240GB. The actual size of the C Drive is 222GB (or 239,203,250,176 bytes) due to the way Windows calculates bytes, which I vaguely understand, but I at least accept.

If I click on properties of the C Drive it shows my Used Space as 92.5GB and my available space as 130GB, but if I go into the C Drive, highlight all the folders and files and click properties, the "size on disk" of these files/folders is only 54.2GB - so I seem to be missing almost 40GB of space, can this be correct.

Equally, my F Drive (which I only use for media), which is published as a 1TB, and has 2.87GB free oand 928GB, shows used space of 888GB (when adding the individual folders together) - again a discrepency of 40GB.

There's nothing in my recycle bin - in case that has a bearing.

This is the first time I've written down all the figures, so I've only really just noticed that both hard drives are "missing" the same amount of space - could this be a clue? Is there something within Windows that keeps 40GB free for other uses?

Is there something simple I missing? Hope someone can explain this for me.

Many thanks, Mark

[CK]

Are you using Vista? If so, Volume Shadow Copy service acquires approx 15% of your total disk space for this purpose.

[Buff]

Thanks for your reply CK - I'm using Windows 7, presumably this service is similar to that on Vista?

I've checked under the services and Volume Shadow Copy is set to manual and is not currently started, but presumably it could still be down to this service requiring the additional space.

15% of my total hard drive space would be close to 175GB, but I'm only(!) missing 80GB - so could it be something else?

Thanks for your help

[CK]

Try downloading a copy of "Treesize Pro" - this will show you graphically what is eating the space on your drive.