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Resolved Question

Wiping free HDD space takes forever (Windows 10)

Sep 16, 2017 6:31AM PDT

In preparation for an upgrade from HDD to SSD, I'm trying to free up disk space on my HDD (after deleting all unwanted files, essentially only keeping the OS + some programs).

What I've tried:
- Wipe free space using CC Cleaner (Thursday to Friday)
- Wipe free space using Eraser (Saturday)
- use generic windows tool to Clean Disk (Saturday)
- cipher /w:C (command line)

I'm also reasonably confident that I deleted enough of my heavy files. Still, about 600 / 900 GB of the HDD still appear to be occupied.
Any idea why this could be?
Thanks!Matt

Discussion is locked

mdiengabc has chosen the best answer to their question. View answer
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Clarification Request
why are you "wiping" or "zeroing" the space?
Sep 16, 2017 8:49AM PDT

Are you planning on getting rid of the drive? Doesn't sound like it.

Best Answer

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Re: free disk space
Sep 16, 2017 6:44AM PDT
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Answer
As kees said
Sep 16, 2017 7:08AM PDT

No need to wipe free space.

It might be easier to install your ssd and reload w10 and your progs instead of trying to figure out what's taking space on your hdd.

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Re: it might be easier
Sep 16, 2017 12:30PM PDT

That's why I asked how he planned to do it.

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Yup
Sep 16, 2017 1:49PM PDT

If they delete the wrong thing from that hdd then they have a busted OS and garbage to clone.
I'll bet there is no backup either.

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Result
Sep 23, 2017 8:17AM PDT

Kees_B was right, I still had some hidden directories with a lot of unnecessary data in them. After identifying these with Treesize Free and deleting them (I also had a full Acronis backup, btw. ), I got everything onto the SSD and booted successfully from it (after changing the boot order) and now everything works fine.

I was of course totally wrong about why my C drive still had so little free space. My incorrect assumption was that I had "deleted" enough files, but that by doing so, I had only deleted the references / pointers to these files, not the actual binary information on the drive itself. That's why my intuition was to try and wipe the 'free' space, in the sense of over-writing everything all that 'unreferenced' space with 0's (kind of like garbage collection, when there are variables, but no more references to them).
So, I think I must have a fundamental misconception about how storing data works, but hey I'm always glad to learn.

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Hdd
Sep 23, 2017 8:31AM PDT

When you delete a file on a hdd all it does is remove the pointer.
The file is still on your hdd but it does not show as used space.
The space is now marked as available so it can be over written.