Looks like the files might have been originally in another alphabet (Japanese, Russian etc) that your system is not set up to display.
You could try installing the extra language support in Windows, but it is possible the file names have been permanently amended.
Problem with that is unless you know which alphabet it originally used, you could end up installing many which could lead to issues later if not configured correctly.
Alternatively, there could have been some sort of security encoding/compression done on the files to stop them being accessible. If that is the case, without the original encoder, it would be difficult to decode.