Thanks omega
First I uninstalled the open beta 1 via the normal uninstall file.
So... i installed it several times and used four different mirrors for the install file. After an uninstall, i checked that the uninstall was complete and wasn't failed.
I removed the intro movies. I thought, if it skip the intro movies, it won't crash. But it didn't work.
I verified that i have enough virtual memory in the windows control panel.
The checksum was okay of every file (i checked this with the JamHashCalculator from this website).