Take the 2-minute tour ×
Super User is a question and answer site for computer enthusiasts and power users. It's 100% free, no registration required.

This question already has an answer here:

C drive shows 1.8 gb free of 50gb on Windows 8 but when I select all the files(hidden files included) and check the property it shows 42.7gb. What could be the problem and what could be the possible solution?

share|improve this question

marked as duplicate by ϺОŞΣŞ, Scott Chamberlain, Tog, Mokubai, Kevin Panko Dec 8 '13 at 22:58

This question has been asked before and already has an answer. If those answers do not fully address your question, please ask a new question.

    
If you want to really check your disk usage, use an external tools like my venerable favorite Sequoiaview w3.win.tue.nl/nl/onderzoek/onderzoek_informatica/visualization/…. the windows tools make some assumptions that are not always clear. –  Frank Thomas Dec 4 '13 at 13:13
2  
More information is required to explain this behavior. This question superuser.com/questions/326578/… has several tools you should use then post your results. –  Ramhound Dec 4 '13 at 13:13
2  
If Windows 8 is anything like Windows 7, you probably have system restore points that can be cleared out. They will take up space, but you won't be able to see that it takes up space due to permissions on the System Volume Information directory –  Lawrence Dec 4 '13 at 14:07
    
Which property says 42.7 GB? Explorer right click/Properties gives two sizes: "size" and "size on disc". Which of These are you talking about? –  Werner Henze Dec 4 '13 at 14:23

3 Answers 3

It also may be 1 of 2 things (or both)

  1. Page File size: If you head to (Control Panel > System > Advance System Settings > Advanced Tab > Performance Settings > Advanced Tab) Under virtual memory you will see that there is some space taken up by the page file. You can remove this or shrink it, though it is not recommended, as this takes up hard disk space.

  2. System Restore: If you head to (Control Panel > System > System Protection) you can head into the System restore configure area, from here you can disable system restore point, which do take up a lot of space, (DO SO AT YOUR OWN RISK) for example on my 320gb HDD, on a new laptop the restore points take up 7gb. So this might get you some more space.

These don't show up when you highlight all the items in My Computer so could explain your confusion.

Hope this all helps!

share|improve this answer

There isn't a problem per se. If I understand you right, you are asking why the sum of the file sizes is less than the disk space used. This is explained by the "quantisation" of file sizes - each file takes up an even number of "blocks" or "clusters" where each block is, in this case (>1GB drive), 4KB.

Thus one file with one character in it takes 4096 bytes of disk space. Microsoft say that the average amount of space that is lost in this manner can be calculated by using the equation:

(cluster size)/2 * (number of files).

share|improve this answer

Have you checked to make sure you emptied your recycling bin? Having a lot of documents and large files in the bin will still use up your precious space.

share|improve this answer

Not the answer you're looking for? Browse other questions tagged or ask your own question.