So, they told me to reinstall windows which I did. That evening, everything seemed to run fine until I started to install my development environment. That's when it crashed once. I managed to install everything and the rest of the evening just went fine.
Now, yesterday evening I wanted to program a bit and the machine crashed 2 times within 10 minutes. I even managed to crash it with the IDE part of the MB disabled so I suppose that this wasn't the initial problem. I've deactivated almost all unneeded stuff of the onboard hardware (Wifi->because it was enabled, driver installed but no antenna hooked on->perhaps a problem here; unused 1394 ports; etc). Somewhere in the ubi soft boards I've read about someone who had stability problems when using 2 displays of different type, so I unhooked the CRT display I used beside my TFT.
The rest of the evening was fine but on the other side: That was already the case *before* I went back to the hardware vendor and when the machine rebootet at least 2-3 times. I have to track this further down.
My son started pre-school today. In Belgium little ones may go to pre-school from 2 1/2 years on if they are clean. My son managed to get clean within 2 days after the school teacher told him he may not come to school otherwise. That little guy really wanted to go to school for the last half year, talking about it every day. One must know that my daughter (5 1/2 years) always tells him what she's done at school.
Gosh... things like this really make me realize sometimes how fast time passes by.