You need to take ownership of all of the files on the drive (as shown in Brian's link, though that is for older versions of Windows, and I wouldn't do it to the whole root drive volume), but that may not be enough. Windows filesystem permissions include an Owner (this user can control the permissions set on the files) and then a separate set of privileges control which users are able to read, modify, or otherwise mess with the files. Setting the Owner only changes the former, and leaves the latter untouched. Your user can own the files, but not have permission to read or modify them.
By default, Windows typically adds Full Control permissions for a special, generic "Owner" user (which points, automatically, to whatever user currently owns the files). However, if you'd previously set permissions manually on those files, those filesystem permissions could point to a specific user on your old computer, which no longer exists (and so will show in the Windows permissions dialog as a UUID string of numbers and letters). Even though your current user owns the files, that does not mean the user has permissions to use them, only that you have the power to fix it for those files if you choose to do so.
So, after you change the ownership for all of the files on the drive, you need to also make sure you have Full Control privileges for the files. You do this in basically the same spot where you took Ownership, except you need to close the file dialog entirely after taking Ownership because Windows is dumb and you don't actually have ownership until you click OK back out (it does warn you about this). Then, you need to re-open the same dialog, click Advanced, and make sure the Owner has Full Control permissions for files on the drive (and make sure to check the And all subcontainers and files option too). If you see any of those weird not-named UUID "users" listed in the dialog, this is almost certainly the cause of your trouble (and you can delete those while you're in there).
When you change them this time, you can specify "Owner" instead of a specific user, and then the permissions will follow the current owner. You could also just apply Full Control to the Adminstrators group, if your user is an administrator.
I generally recommend against selecting the full disk (as shown in Brian's link). First of all, if you do this, you will get Access Denied errors for certain hidden files and folders owned by the system (the Recycle Bin for the drive, for one). But volumes are also typically owned by the SYSTEM user, which may sometimes matter for maintenance tasks and other things. Instead, you can select the all of the top-level folders on the drive and apply the Ownership and then the Permissions to these folders, and that won't pop up the access denied prompts (or should not, if so, something is then wrong inside the folder), and you won't muck with the regular volume ownership in Windows.
Very nice, specific and modern instructions for this are linked from the Wiki, which I posted above. If you look at the Windows 10 specific instructions, you'll see you did steps 1-5, but not 6 and on. That's what I'm talking about above.
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Topic: Trouble Deleting Files in JRiver [Solved] (Read 4813 times)