Try making the \bin entry first, sounds like it matched the first instance it saw mentioning mariadb.
Code:
C:\Program Files\MariaDB 10.0\bin;C:\Program Files\MariaDB 10.0;C:\Program Files\MariaDB 10.0\Data
To be honest, I didn't think the others are needed, pretty sure my instance only has the \bin dir listed.
Code:
C:\Program Files\MariaDB 10.0\bin;