[SOLVED] Permissions change preventing Windows 10 from booting

[Smokes7689]

Hello everyone,
I've created an issue with my system that I've been unable to resolve after a lot of research.

I have two hard drives in my PC. My "main" drive has my Windows 10 installation on it, which I've been running since early 2020. My "secondary" drive is used for storing extra files.

While diagnosing a separate and unrelated audio issue, I formatted my "secondary" drive and created a new Windows 10 installation on it. I was trying to test and see if the audio issue was still present on a fresh Windows install. While doing this testing in the new Windows 10 install on the "secondary" drive, I tried to access a video file on my "main" drive with my old Windows installation that I've been using for years. I got the small pop-up that said "You don't currently have permission to access this folder. Click Continue to permanently get access to this folder." Unfortunately, I was foolish and didn't think much of it at the moment, and I clicked 'continue.' This seems to have modified the permissions for my entire "main" drive to this new Windows 10 installation on the "secondary" drive, and now I can't boot into my old Windows 10 install on the "main" drive.

I'd like to avoid starting fresh, so I'm hoping to find a way to reset the permissions of my "main" drive so I can boot into my old Windows 10 installation and continue to use it. But after looking into this, it seems that I must be logged into my "main" Windows install in order to re-take permissions of files and folders, which is not possible now since it wont boot up in the first place. I was exploring some options of using command prompt with the Windows installation disk to modify permissions, but I didn't try this yet because I was unsure of how to do this properly, and I didn't want to make the problem worse. Most things I've read while researching this issue are saying that I'll need to format the drive and start fresh, but I wanted to see if anyone had any ideas of how to get around this.

I apologize if this was confusing... I tried my best to explain it clearly. I'm happy to provide any additional information or details about the issue.

Thank you for your time, I really appreciate it!
Tim

 

[USAFRet]

Why have 2x bootable windows installs?

Yes, you screwed up the permissions on the old OS install.
This leads to issues, such as you see here.

 

[Smokes7689]

Why have 2x bootable windows installs?

I had an elusive audio issue, and after unsuccessfully trying a bunch of things to fix it, I wanted to see if it would still happen on a fresh Windows install. But I wasn't sure if a fresh install would fix the audio problem, and I didn't want to wipe out my original Windows installation if I didn't have to, so I figured a fresh install on a separate drive would be a reasonable test. I also thought this would help me to determine if the audio issue was hardware or software related. Everything seemed okay until I made the dumb mistake of trying to access a file on my main drive... very bad idea in hindsight.