this ALWAYS happens:
I have a Windows 10 PC with five hard drives, each one functioning as a partition. I use the C: partition for the OS and the others for data, backup, and so on. The partitions are C:, D:, E:, F: and G:.
Eventually I had to format my C: drive to get a fresh Windows installation. But the hassle was so strong I regret doing that: turns out the previous installation assigned an user identity to each partition (SID?). Now, I can only access the C: drive and, curiously, the D:, but not the E: to G:. (By the way, the current D: is the former F:, which got the drive letters swapped).
I inspect the security tab under the properties of the drive, and I see 'SYSTEM' and 'Administrators' have full access and control, as well as a rogue "unknown" account beginning with letter "S" and a bunch of characters. I deleted those.
I am the only user of this computer (with a Microsoft account) and the account type is 'Administrator'. But I still can't access those drives; I get an 'Access denied' message. Question 1: Why is that?
The weak solution is to take 'personally' possession (assign a user-based permission, which is not recommended) – have my user (Microsoft) account become the owner and have full access. The problem is: this assigns this new identity to ALL files in those drives, and one contains my 650GB Dropbox folder, while the other contains my equally 650GB OneDrive mirror. Since all files' metadata are modified with this procedure, I have to resync ALL my data to both clouds all over again, which is unacceptable.
Question 2: How can I prevent this from happening next time I format my C: drive?
p.s. I can't use the
icacls * /T /Q /C /RESET command because I don't have access to those drives to begin with.