How is Win 10 eating up my c: drive space?

Prior to installation, I had less than 100gb on my c: drive. Now, it's closer to 300.

I'm past the time for reversion--so, I don't think it is files from Win 8.1 (from which I upgraded) but that's one possibility. (However, I can't find them.)

--Maybe it's restore points? Hidden volumes?

When I clicked "show hidden files" in view from File Explorer, though, no hidden drives showed up.

I went through my Program Files and Documents directory. They seem about where they should be.

So, where in the world is that extra 200gb of data stored? I'm wondering what can possibly be happening here? I'd add that it only happens on my desktop, not my laptop. It's possible I clicked some setting on one and not the other.

Suggestions welcome!

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When I go looking for this.

I use apps like tree size and windirstat ( ) but I'm not finding any Windows 10 specific issue to date. That is, the same old restore cache is the repeating find.

BUT THIS IS A GOOD THING!!! I've lost count of the number of times System Restore has saved an OS reload. Why not let it work or if you need space, turn it off and back on?

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I don't mind having some degree of restore points, but I backup regularly with Acronis and Symantec. Windows is not my principal restore solution. Again, I don't mind having yet another hedge. But the real reason I object to this is not because I'm out of space, but because it's changed quick, easy C: drive backups to long, annoying ones that eat up my external backup hd. So, it's actually preventing me (or at least adding some annoyance headroom) from doing more important backups....

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It's likely your restore points. How big is your C: ?

Restore points take a percentage of your C: drive. You can change that percentage if you wish.
Good luck.

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huge restore points

Yep, I think that's it.

I had 256 gb committed to just THREE restore points. I had the % slider at max, not limiting space at all.

As an experiment, I changed it to 10%---and 2 of the 3 restore points were deleted. The most recent one was 28 gb. (That seems like an awful lot just to install DirectX.)

The most important restore point was an Oct 30 restore point on a Windows update to the main program. I'm guessing that probably took the vast majority of the space in question, since the only other restore point was Calibre, and that certainly shouldn't take very much space.

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BTW, I reduced the slider to about 10% (100gb or so). What is a typical default considered to be? I think to be worthwhile, there has to at least be one restore point capable of being created when major win 10 updates come through.

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On the Win 10 sys I looked at I've got 3 in 12 GB.

I'm not sure about the numbers you quoted from your system. I see the last Insider update I installed turned System Restore off, so I turned it back on and set it at 10% of a 120 GB SSD. Then I manually created 3 restore points, and they all fit in the 12 GB allotted. On my Win 7 laptop I have it set at 4% of a 250 GB partition, and I have several restore points. I like to have at least 3, but you can set to whatever suits you.

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Hmmm. Maybe not every restore point is the same size--from what I saw they were not of equal size. Perhaps it's more akin to an incremental save, only keeping files modified from the base configuration.

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I did the test of creating a restore point even though nothing had changed. It took up no space at all. Clearly, not every restore point is equal.

So, I guess the real question is that when a major win 10 update comes down the pike, how much space might one expect that to take in creating a restore point? There may be no real answer.

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Disk space is still cheap over system recovery.

I think I set it to 100GB so it can have space to keep many points. Never really looked too long into what the minimum could be.

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thanks, I guess this is solved

It's not really a question of disk space per se, but of slowing down my imaging backups that I do daily by tripling their size.

Perhaps there is some way I can tell SSR and Acronis to exclude restore points from the backups. I'm going to ask them.

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Or before backup turn off and on SR?
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I never really thought about how much space they take.

I've been running Windows for about 20 years and never seen any documentation on how MS creates those restore points. I'm inclined to think they haven't published anything. If you want to pursue that, you might want to post the question in one of the MS forums at
Back when a 60 MB hard drive cost $200 we worried a lot about disk space, but now days when you can buy a 3 TB drive for $80, it's not worth most folks' time to worry about it.
Good luck.

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check disk management

did you check disk management to see if there are any additional partitions? when you upgrade to win 10 you will get a windows.old folder, did you delete it or holding it for just in case?

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Windows 10 spacing

I don't know about windows 10 because it rare use for anyone and also very useful for us
and other is eating up space in c drive, well i don't know it's true because windows 10 is basically good version f windows and high performance and compatible for all students, professionals.

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When you upgrade Windows

you are given 30 to go back to the OS you upgraded from and It saves a file called Windows.old that will be on you machine for 30 days. After the 30 days you have to use then restore disk you got with your machine or you were supposed to create.

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