I have this case: on Windows 2012 /SQL server 2012 i have installed four SAP instances.
I can only start up two instances - then the third an fourth system won't start? I think it´s some kind of memory problem, but i can see from Task Manager that still theres is plenty of free physical memory.
It´s not a particular system who have problems. i.eg. i can start system 3 and system 1 or system 1 and system 2.
I think i have used some memory setting ealier to solve this, but i forgot :-)