Errors in the event viewer are not necessarily something to worry about. What you are looking for in event viewer is an error at or shortly before the freeze. It can be hard to decipher what the errors really mean. I don't speak/read German, it looks like Karl does, he should be back before long.
The idea of disabling half the startup and services is to speed up finding which group has the problem. After you find the half with the problem, you will start disabling each entry one at a time. Reboot after each change.
It would not hurt to run sfc to see if there are any corrupt system files. Type CMD in the search box and right click on cmd.exe and select Run As Administrator. At the command prompt enter sfc /scannow (notice the space after the c). It will look for and try to repair corrupt system files.