FS Crash Problem

Hello people,If i start a flight no matter where, after a little time (with some aircrafts earlier, some later) a little black box under in FS appears and i can fly still but i can't reach te FS menu, can't close FS and if i want to open Task Manager (CTRL+ALT+DEL) i hear a error message but never saw one. With the PMDG 737 i get it in about 1 minute, if i click on a PFD i hear some messages and FS closes. This happened on some earlier installations (even Windows installations), i did a new FS installation today and i have the same problem. I have no idea what causes the problem. I'm stuck at this.