So I'm wondering is there a way to have a text file editable only by certain local users? In other words, if I were to open the file in another computer via flash drive, is there a way to prevent someone from changing both the file contents and (especially) its permissions?
You have to become the owner of the file (just making the makes you the owner). On non system disk (where win7 itself is on so C): All users have FULL ACCESS of the root folder. Since subfolders and files inheret permissions of parent by default... all files and folders can be read/write/delete/execute by all users.
You want to prevent access to file(s) or a whole folder (or multiple folders)? Or whole disk?
Just right click the file->security->advanced. Disable inhereted permissions form parent. Add yourself to the list (if not already listed). Give yourself full permission. delete inhereted permissions! press OK multiple times. Test if is working.
Adminstrators can still do anyting though!! They can become owner of the file and change permissions... So they can regain access again.
What version of win7 do you have (home premium, professional, ultimate ....)?
For ultimate and professional you can better encrypt the file. Encryption is much better of course
Encrypt or decrypt a folder or file
How Do I: Get Started with the Encrypting File System in Windows 7?
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