[Users] disable ballooning mode

I'm trying to get virtual windows and specific software on it working. Windows is working fine but i'm getting blue screen when trying to start this particular application (which works fine in vmware). I figureout that there could be some kind of problem with memory. My question is about ballonning memory: is it on as default ? If yes, then how to disable it ? Did anyone also discovered such problemes ? -- Michal