Official Support is available to registered Toontrack users only.
Access to the appropriate private boards is automatically granted on registration of a Toontrack product at:
https://www.toontrack.com/my-products/?sp=true
If, as a registered Toontrack user, you are unable to access the Official Support area by following this http://www.toontrack.com/forum/
please contact the Support Team using the support webform located at http://www.toontrack.com/faq ,
including the serial number for your product and your forum ID (login name at this forum).
PS. You don't mention for which product you are inquiring...
There may be different, product-dependent procedures for moving the default MIDI file location.