“Disk full” in Windows 10 – memory leak?

My C: drive is 3GB away from "disk full" It's a 750 GB disk. I am on Windows 10. This is especially remarkable, since I store very little of my "live" data on the computer -- almost everything is on USB drives and cloud.


How do I find out where all the storage is being used?


One possibility is that I create and delete accounts on this computer fairly regularly. When I delete accounts, I sometimes get the message "Cannot delete account for a user that is logged on" -- but that account is logged off, and it gets deleted anyway, so I haven't worried about it. Might there be files that aren't getting deleted?

This is NOT the "100% disk usage" thing with several other articles, relating to Windows Search and Superfetch -- the disk is not busy, it is full.


Please start your answer right at the beginning of the instructions -- I used to be a very sophisticated programmer, but lost hold of Windows somewhere around Windows XP. I removed all the Charms and other Windows 8 crapware. Please start your instructions to me with the START button or with WindowsKey/R or something else that is unambiguous and not likely removed.


Thank you.

I right-click Start, left-click Disk Management to view the drives which will show the partitions and the size they are. Right-click each partition and choose Properties, will give information to how full each is. There will be more than 2 partitions for each physical drive.

Thank you Tairiku! Treesize gives me 80% of a diagnosis. In $Recycle.Bin are over 20 sub-bins of about 30Gb each. 560GB total of Recycle Bin. Now I have to figure out where each one came from and which ones are most painless to delete.

Files in the Recycle Bin are backups from things you have deleted from your system. So clearing the Recycle Bin will not harm your system as those files are no longer being used in the system. It's there in case you deleted something and want it back.

Jim

Oh geeze louise. Now I'm on to the next layer of the problem.

Treesize tells me that 600GB is tied up in recycle bins. I get the names of those recycle bins, about 20 of them --
S-1-5-21-1251185382-[lots more digits]
but I can't find those directories to delete the contents. From the admin account, when I go to Recycle Bin, the folder is empty. When I use Windows File Explorer to search for folder names with "1251185382" in them, I find RSA encryption stuff, and DSS encryption stuff, and lots of other security stuff, but not recycle bins.

How do I get to these 20 recycle bins to empty them?