Unknown User Permissions

Hey guys,

Recently I reformatted my hard drive and put a clean install of Windows 7 onto it, but I'm having a problem with a folder on my external drive now (note: I didn't reformat the external drive and the OS I had before was also Windows 7). On my external drive I have a folder labeled, "Media". Somehow the folder's security settings have been messed up. There are now two unknown accounts under the Security tab that I cannot delete (nor can I even add another user). The general names of these unknown accounts are "S-1-5-21-*". I also found the accounts on a few other folders on the drive, but I was able to delete those. The Media folder is the last folder (as far as I'm aware) that has these accounts under the Security tab.

This is quite a problem because due to these accounts I cannot write into the folder. I can read everything, but I cannot write. I'd really rather not reformat the drive because I have roughly 500GB of data on the drive and I do not have anything else that can hold that much information.

I suppose one option could be to create a new folder and transfer the data into it, but I wouldn't be able to delete the original Media folder afterward so I'd rather find a way to eliminate the accounts.

Thanks in advance for any help!

EDIT: After some further investigation I discovered that the subfolders of the Media folder also have these unknown accounts under their Security tab. I also went into the registry editor and attempted to delete the user accounts, but I keep getting an error that says they cannot be deleted. If I dive deeper into the registry editor I can delete certain folders under the account's registry entry, but if I attempt to delete one that cannot be deleted (I receive an error for), all of the other folders I deleted will return. This sounds like some sort of malware. Should I be concerned?

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New Member
I won't say it is not malware,,, but it doesn't exactly sound like it, that I am aware of.

I would not say these accounts carried over from an old install unless you didn't format the drive before installing the OS.
I do not believe these accounts would populate the registry, just by showing in the security tab of a folder on an external drive. But unfortunately I also can not say, it is not possible.

I would, at this point, (mainly because of what you were doing to the registry) backup data,,, pull the external drive off,,, reformat again the main drive,, and start over....

During the install,, delete the partition, reboot, then begin the install. This will hopefully make it believe there is nothing on that drive before beginning the install again. Could be cross corruption or something?

I am only guessing though.


Extraordinary Member
ITt is not at all serious. When you reinstalled your main OS, the existing "owner" of the folder, detected a change and set up a sequential account. The numbers are merely a random name for an ankown account. The mystery to me is why it would have changed permissions.
JHowever, the problem is easily resolved. I can take you through the security permissions, but the easiest way is to take the aattached file and in the zip you wil see a .reg called "Take Ownership". Run it and it will place a right click mouse option on the drop down menu. <take ownership of the folder and you willbe able, if you wish, to delete the offending account.

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I don't know if this will solve anybody's problems or not, but here is what I did:

1. Boot into Safe Mode
2. Navigate to the folder you are having problems with
3. Delete the "Account Unknown..."
4. Edit the permissions for the folder
5. Reboot

In my case, this fixed the problem. I can now open the files in that folder.



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