'Used Space' on disc incorrect

I have noticed on occasions that the 'used space' on my master (C) disc can vary quite largely for no obvious reason. To get straight to the point, it is currently reporting 10.8Gb used, when not so long ago it was reporting around 9Gb. I have certainly not added anything that would amount to 1Gb or so, and having checked the size of all the folders in the root directory of C: (including the hidden ones) they sum to 6.7GB !! Anybody know why there would be a 4Gb difference?

 

The additional space could be from hidden files and folders, protected files and System Restore points.

 

Hi Tony,

Whiskeyman is correct in that System Restore points can eat some real estate.

And I know this is going to sound really dumb, considering how long you've been around, but cache, cookies, history, temp files, et al, along with the SRP's can account for a lot of space, too. And, don't forget updates to your system and programs (AV and AS malware definitions updates)(plus if you've upgraded your browser), log files from the programs, Java cache: which if all taken into account can easily add up to near 1GB.

I trust you've emptied all the above and deleted all but the most recent RP's and done a couple of defrags?

Another poster (I don't remember who ) gave a link to a nifty, free, self-contained cleaner called "ATF-Cleaner" that really works well.
http://www.atribune.org/index.php?option=com_content&task=view&id=25&Itemid=25

 

Thanks Whiskeyman and Chris. It's definitely not temp, log, cookies, or junk files - I run cleaner programs regularly and, yes, I defrag regularly. It can't be upgrades either as these will form part of the program or Windows files, which are included in the 6.7Gb and in any case, I haven't had any recently (Windows auto updates is turned off). You may have a point about Sys. Restore - I will think about that.

 

Pagefile ?

Have a look at it. By default, Windows is configured to expand or shrink it as per requirement.

 

Hi again and thanks to all. It turns out to have been System Restore, as Chris suggested. Cleaning that up reduce the 'used space' by just about 1GB ! As they say in the classics, you learn something new every day.

 

Hi Tony,

Whiskeyman originally posted the SR points, but thanks for the update and I'm glad you regained some acreage.

As a quick p.s., When you update a program, it's usually larger than the original. For instance, ZoneAlarm v. 4.5 is about 5,000 kb, while ZA v. 7.0 is over 15,000 kb. Same thing with Flash, Shockwave, Java, your browser — you name it.