Completely out of scope of the project. If you are afraid that someone could tamper with your computer, then lock the whole session (Win+L), instead of every single applcation you care about (you can also set up Windows to lock the session automatically after some idle time). If you are afraid that someone can steal your files, encrypt your hard drive using BitLocker or VeraCrypt, etc.
There is no reason at all why this should be done in OpenMPT (or any other application that is not security-sensitive) instead of the operating system level where it's already possible.