Disk Management Is Seriously Misreading My Storage

I recently tried to uninstall McAfee from a brand new HP W10 laptop using the McAfee Product removal tool, but the uninstall quit partway through the process leaving me with half a program that couldn't run or uninstall either.
I didn't know what else to do so I finally reset my computer so I could start all over.
Unfortunately the removal tool failed and stuck again and I had to reset the computer again, only this time the Reset stuck at 40% completion. After waiting 2 hours it was still on 40% and not moving.

Finally I decided to shut it off and restart. When it started, it said "A configuration change was requested to clear this computer's TPM Module". It said press F1 to continue or F2 to not. I pressed F1, it rebooted and started up.
I downloaded Revo to get rid of McAfee and finished setting up the computer.
The computer has been running fine since then.

But here's he problem.....I have a 1 TB SSD and I just discovered that Disk Management recognizes 940GB capacity but it says there's only 16GB free, and that is totally impossible.
Speccy (Piriform Software) agrees there's 940GB capacity but says only 2% free space. What's going on?
I have no games, very little music and nowhere near that much software.

The computer thinks I'm using 98% of my C Drive and I'm only using a small percentage! What happened?
I'm sure there's a connection with what happened with that reset, but what do I do now?

Thanks for the come back dalchina. It wouldn't perform the chkdsk. Here is what it said:

C:\WINDOWS\system32>chkdsk C: /F
The type of the file system is NTFS.
Cannot lock current drive.

chkdsk cannot run because the volume is in use by another process. Would you like to schedule this volume to be checked the next time the system restarts?

I didn't have any programs open, unless it's complaining about Kaspersky running in the background or some other background process?

You are booted into that drive, therefore it is in use. That is what it means by "another process".

DC10 said:

Would you like to schedule this volume to be checked the next time the system restarts?

If you say "Yes", it will schedule a chkdsk to run when you reboot the PC, before Windows starts.

I'd delete it - especially with a name like that.

If you google Reset_SafeToDelete_OverwriteSpaceFile_0.tmp that is what everyone else who got it did.

Run TRIM on your SSD after.

DC10 said:

.
...........I right clicked the C: Drive in Disk Management and guess what I found.........the culprit!
A file, not a folder but just a TMP file labeled: Reset_SafeToDelete_OverwriteSpaceFile_0.tmp, and the size of this file is 878GB!

So Disk Management is not misreading my storage, it's actually there....878GB worth in just 1 file!
It's located in "This PC >Windows (C)" Everything else in this location is all folders except for this single TMP file.

Well I finally went in and deleted the file "Reset_SafeToDelete_OverwriteSpaceFile_0.tmp" which was an 878GB file and everything appears to be back to normal. This ridiculous file somehow snuck in the back door as a result of that 40% Reset I mentioned in my 1st post. If you Google the name of the above file you'll find that my case was not the first, there's been a few others.
Out of all my years with W7 I never had any really stupid problems like that. A few problems yes, but not really stupid ones like this. 7 was a great OS. Leave it to Windows 10.

lx07 said:

I'd delete it - especially with a name like that.

If you google Reset_SafeToDelete_OverwriteSpaceFile_0.tmp that is what everyone else who got it did.

Run TRIM on your SSD after.

"Run TRIM on your SSD after"?
Manually? I thought that was performed automatically......how do I do that?

I have a Samsung SSD and they say all their SSD's are TRIM capable and I checked and my computer says TRIM is enabled. I hope so.

Go to Defragment and Optimize Drives and click on Optimize

It will do it automatically (eventually) but as you've just deleted a file that took 99% of your disk it is worth doing it manually just this once. It will carry on with its weekly schedule after that as normal.