You must have installed SEMC USB flash driver -> install SEUS and SEMC USB flash driver will be installed automaticaly.
When connect to XS++ v3.1 hold 2 and 5 together instead "C" button and put USB cable.
HB1-06_Generic_CDA102568_12_R4A_GENERIC_EUROPE_3 can find here: Downloads -> Custom Files -> k800custpack