One reason why the ILS may not become active is if the frequency is different in the AIRAC file to the one in FSX.

To check the frequency for the runway you are approaching/landing, got to the Menu > World > Map, move the map until the airport is in the centre and zoom in all the way, then click on the airport. When a box appears, select the airport from the list (usually it will show all nearby objects like VOR, NDB, intersections/fixes as well as the airport). On the left side will be all the info for the airport including the runways ILS frequencies & headings. Note. Sometimes the runways can differ from the AIRAC!

Once you have the info you need, return to you flight, open the CDU, click on the NAV RAD and see if the frequency matches. If it doesn't, you need to enter it manually in the LSK 4L, in this format xxx.xx\xxx (i.e. 110.10\054).

As for the AUTOLAND, the 3 A/P switches will become active (turn on) automatically once the ILS and GS are captured and the 767 is about 5nm from the runway threshold. You should not need to turn them on manually.