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Summary: Depending on how you look at your disk, the amount of space used can appear quite different. We'll look at some of the possible reasons.
It's worse than you think. Just with a little poking around I was able to generate several different numbers for the "spaced used" on my hard drive. I'll admit, it's frustrating. Fortunately it's not something we need look at very often, but you'd think the line between what's used and what's not used would be clear. Actually it is, but there are different ways of looking at "what's used" that don't tell the whole story. • First let's look at the two examples mentioned in the question. Here's Windows Explorer's view on my C: drive, by right-clicking on the drive and clicking on Properties:
As you can see, Explorer reports that about 47.8 gigabytes are in use, and that 24.6 gigabytes is available as free space. If you're just wondering about the free space on the drive, or how much of the drive is in use, these are actually the numbers I'd use - they take pretty much everything into account. Now, back in Windows Explorer's view of my C: drive:
Click on any file at the root of C:, and type CTRL+A to select All files. Now, right click on any of the files selected and click on Properties:
You can see that Windows reports the size of all files in C:\. It reports both size, and something called "size on disk". And neither are the close to the 47.8 gig reported to be in use earlier. "There are a number of issues that contribute to the
difference..."
Let's clear up "size on disk" first. Windows allocates space for files in "clusters" or "allocation units". The size of a cluster varies, but ranges from 512 bytes to 32K or more. On my C: drive the allocation unit is 4096 bytes. What this means is that Windows will allocate 4096 bytes for any file or portion of a file that is from 1 to 4096 bytes in length. A 1 byte file? That takes up 4096 bytes "on disk". 100 byte file? Still takes up 4096 bytes on disk. A 4097 byte file? That takes up 8192 bytes - one complete 4096 byte cluster, plus another 4096 byte cluster to hold the extra byte. So in determining how much disk space is used by the files, we need to pay attention to the larger "Size on disk" number. But that number is still very different than the 47.8 gig. There are a number of issues that contribute to the difference:
There's probably much more that I'm not aware of that enters into the picture as well. I know in researching this issue there was no way I could actually get all the numbers to add up. Possible additional culprits further confusing the situation include compressed files (which appear bigger than they really are on disk), junctions and shortcuts which may or may not be counted as files, utilities which may or may not include the recycle bin as part of the "spaced used" since the contents have technically been deleted, and Windows Vista's ability to keep additional versions of files automatically (though where they're kept and how they're managed, I'm currently not sure). So yes, it is confusing. But as I said earlier, I would rely on the drive properties to tell you about the actual used/unused state of your drive. Related:
Article 11769 | Posted August 19, 2007 |
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![Properties of All Files selected in C:\](/images/allfilesproperties.png "Properties of All Files selected in C:\")
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I agree with your opinion But If somebody uses RAID if it shows like that how you solve this actual folder size 305 GB and properties shows 545 GB how what are the possiblities
Posted by: Amol at August 22, 2007 10:06 PMI recently had a problem similar to the poster here. I have a 75 gig hard drive and only about 2 gigs that were available for me to use. I checked with Windows Explorer where all the space was being used, it sure wasn't the Programs or Photos or Videos, all but Programs are Space hogs. I usually always store my videos and photos on another drive besides my System drive. So I look and look and finally I found where most of my available space was used, as weird as this is it was in the Windows temp files....a huge amount of space was being used by the temp files, like 26 gigs of space!! I wasn't sure if I could just delete these files and why it was keeping so many temp files anyway. I called the Microsoft Tech dept. 800 number I have handy and just asked if I could delete these files, first they gave me the run around and that I might delete something important, so I asked for someone that knew more, they connected me to a tech guy and he told me to just delete the files it was nothing important and that it shouldn't cause any problems. He did walk me thru it and at first we tried from the normal start up to delete the temp files and it kept bringing up files that it said it was using, hmmmm, anyway he had me boot into "Safe Mode" and from there I was able to delete the whole thing, he had me type in %temp% into "Run" and it deleted the files with no hang up's or problems, it worked wonderful, no problems afterward and it created a huge amount of free space on my system drive. What a relief, but as far as a good reason why there were so darn many temp files I have no idea...all I know is that is stupid if you ask me and it should limit the temp files it keeps, and should in no way, shape, forum, or fashion keep that many temp files. I looked at the temp files before deleting them, it had photos, videos, system files of some kind and just about anything was in there. Their gone now, haha, anyway it helped me a bunch and it sounds like what the poster here might have, I found the temp files buried under "my documents", and its not the temp files listed in the breakdown in Explorer towards the end under the system drive. Good Luck and I hope this helps someone else.
Posted by: Charles L. Grubbs at August 27, 2007 11:22 PMCharles,
I have this problem with both my C: and D: drives.
The properties of my D: Drive shows "Used space: 214 GB". The properties of all the files and folders show "Size: 133 GB".
The properties of my C: Drive shows "Used space: 135 GB". The properties of all the files and folders show "Size: 90 GB".
Where are the temp files on the C: drive? I have Windows Vista, and the folders are organized differently than XP. My files/folders are in C:\Users\Curt. In this folder, there are these folders:
Documents
Downloads
Pictures
Videos
etc.
Approximately 80 GB is used up somewhere on my D: drive. Does anybody know how to get it back on a Windows Vista PC?
Posted by: Curt at February 19, 2008 3:02 PMI'd got the same problem but I just resolved just to searched about new features in vista. When I saw this Volume Shadow Copy, OS automatically backup my C drive every night by default so I did delete my recent backup. 20gb of unknown data were gone.:D
Posted by: Jesus L. Saavedra Jr. at June 3, 2008 6:43 AMThanks for this post. The comment from the user above led me to a solution for my situation. I was working on a Lenovo T60 with a 120GB hard drive. Only 16GB were showing free in the C: properties, yet selecting all files, including hidden and system on C:, showed only 46GB in use. There was a hidden Rescue and Recovery program built into the laptop. It had automatic backups that presented no notification. I turned off the scheduled backups and deleted the backup files. This resulted in the drive having 60GB free! Thanks!
Posted by: Matt at August 1, 2008 11:37 AMSo frustrating. This comment is describing to a tee the situation I am facing but unfortunately the solutions others have found don't seem to apply or resolve my 44G discrpency.
I have no hidden backups, I'm showing hidden, system and OS files, I do not believe that I have RAID, and my %temp% folder has only 343MB in it.
I am assuming that the Directories, MFT, and log file referenced above do not accound for 44G of space. Is there a way to see how much space is used for these three items?
Any other suggestions?
How can I confirm that there is no RAID setup on my machine?
Posted by: David Kahn at August 3, 2008 1:30 PMI have a much more confusing problem than that. Whenever I delete something on my computer, I LOOSE space, not gain it. I've done several virus scans and nothing has been picked up. For example, I had 194 GB of free space on Disk Drive C. I deleted a 2 GB file (using windows vista's uninstaller) and I suddenly had 193 GB of free space left. I dont think this makes a huge difference but im running Vista Home Premium 64-bit.
-Leo
Posted by: Holden Kripacz at August 12, 2008 8:34 AM
I have exactly the same scenario. I downloaded a program called HDGraph from SourceForge to analyse the disk space. THe program says that it cant read 40G of data due to permission issues/bad sectors adn what not. I have tried posting it to Vista forums as well with no replies. Plz help
Posted by: Matrix at November 7, 2008 7:06 PMA lot of space can be cleared by turning off system restore in control panel
Posted by: Poo at November 7, 2008 8:10 PMTo say it better,System Restore Points are calculated in size when you right click your drive and see the properties,but when you go into the drive and select all and right click and see properties they are not added to the total size you see there.My 60gb HDD had a 8gb difference, turning off System Restore fixed the discrepancy.
Posted by: Poo at November 8, 2008 7:54 AMBut you also lose the benefits of system restore.