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I am having a problem with my C Drive as it continually loses free space. I keep backing up and deleting files, but the easy ones are all off (those folders that are 100 MB and larger that can be easily moved or backupped and deleted from the C).

I did free up the 100 GB drive to 8 GB, but a couple of weeks later it was down to 4 GB. I searched for new or modified files in that time, but there was no substantial files (bigger than 1 MB). So I am not sure why I am increasing usage / losing free space.

I used to find out where my disk space is has gone, but could not see any change either.

I have norton anti-virus, but it hasn't found anything.

I thought maybe it had something to do with the two large .sys files, but with 3 GB of RAM, my friend tells me the sizes of my hiberfil.sys (3.15 GB) and pagefile.sys (3.45 GB) are appropriate.

I have also tried defragmenting. For some reason, this made it worse. Recently I removed files to go from 3 GB free space back up to 5 GB. In that time though, the free space dropped to 4.6 GB. Then when I ran the defragment tool on Vista, the free space went down to 2 GB!

Any suggestions?

(Side question - the only other thing I can find to delete of considerable size is .cab files in the C:\Windows\SWSetup. It seems they are tied to programs. Can I deletes these files, especially if they are all older than 2 years old?)

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Do you have any backup software installed? – RonK May 23 '11 at 15:27
The SuperUser Blog has a few articles regarding missing hard drive space at… – Mokubai May 23 '11 at 15:41
yes RonK, thanks. I have back up software that came with my Western Digital external hard drive - WD Smartware . . . The timing of the problem may coincide if that is what you are thinking. . . . Sehe did below correctly identify that Vista's backup restore is running wild (UNBOUNDed). Might be connected to the WD Smartware software. I am hoping to hear how much I should limit the size to. – user82585 May 23 '11 at 16:58
Thank you Mokubai, I am trying the Advanced SystemCare 4 from page 3 of the link from your link. Still, I think the main problem is provided below. – user82585 May 23 '11 at 17:11
BTW Mokuai, I ran the Advanced System Care 4. It cleaned up thousands of problems, but did not free up any C Drive space. So while I am sure it is helpful and a good program to run, it did not address the problem I am experiencing. – user82585 May 23 '11 at 17:37
up vote 3 down vote accepted

You may (as in likely) have system restore points enabled. You can clean those up, and put a maximum on the volume used for restore points

Here is one guid on how to do that:

share|improve this answer
An of course the Disk Cleanup app if you haven't already run it. – Spectre May 23 '11 at 16:09
The directions on the link are very helpful. Since I am using 26 GB of Shadow Copy Storage, 27 GB Allocated and the Maximum is UNBOUNDED, I believe you are correct! Thank you very much. The link also provides how to reduce or limit the allocation for this functionality. It does not say how much I should allocate though. Can you recommend how I figure this out? – user82585 May 23 '11 at 16:52
Yes I did run the Disk Cleanup Spectre. Thanks. – user82585 May 23 '11 at 17:01
@sehe, please see the question above on resizing the Shadow Copy Storage Allocation. Thanks! – user82585 May 23 '11 at 20:56
I'm by no means an expert on administering Windows systems (I tend to stay away :)) but here goes. I reckon a healthy Vista installation should be 10-12Gb (for the OS + basic tooling). Add some WinSxS (8Gb?) room and some space for shadow copies (say, 12Gb): a toal footprint of 32Gb ought to be enough. But, hey I'm on linux because I think Windows fills up my SSD far too quickly – sehe May 24 '11 at 0:31

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