NoVirusThanks File System Protector is a powerful tool which can limit access to the files or folders you specify. This could help you create a hidden folder which is much harder for others to access, and might offer some DIY protection against ransomware by allowing only specific apps to change your files.

The program has options to prevent processes from opening or modifying particular files, file types or folders, and you can refine this by creating "exclusions"-- programs which are allowed to do anything.

This is a little more complicated than you might expect, because there's no GUI to define these rules. Instead you must edit plain text files. Here's an example from the default settings file.

; Deny ALL processes from modifying specific files by filtering file extension
[%OPER%: DENY_WRITE] [%PROC%: *] [%FILE%: C:\ProtectedFiles\*.txt]

Although this isn't convenient, it's not difficult to understand, either: the rule is blocking attempts to write to the specified file type and location by all processes. Replace the path with your target folder and file type - C:\Locked\*.* - and your programs (or any malware) won't be able to change anything in that location.

An Exclusion system allows creating super-applications which aren't affected by any of this. These rules are also stored in a text file, although they're much simpler, and are essentially just the process name.

*\notepad.exe

This would allow Notepad to open any file, even in a locked folder.