I do not know if i make a fool of myself now,but this is what works on my pc:(often tested)
if you happen to install a new update for cubase,just delete the cubase.exe out of the Steinberg/Cubase4 folder before you apply the update.
So if everything works fine now it's o.k..
In case Cubase is crashing or update does not work for whatver reason,just delete the newly created cubase.exe again out of the folder and go to the bin and restore the old cubase.exe(hold the mouse on it and it will show the version).
I tested this only for updates "within" one version(3 or 4 ).
You might say how is it possible to run the application core with -in this example-an older .exe file.This smakes me wonder as well.
So may be this is part of the current cubase4 problems-update process does not work properly.
I updated from 4.01 to 4.1 and even have been able to start the application!
All the features of 4.1 have been available-though i got the problem that the asio system was not initializable.
After deleting the .exe and restoring the older .exe file cubase(then 4.01 again) worked again and the features of 4.1 have not been available any more.
I guess this is more like a bug,but i did it like that several times(i always checked if i got the same results-asio bug and so on- by deinstalling cubase completely)and always got the same results as if i completely de- and reinstalled cubase(old and new versions).
I did it the same way with the current 4.12.
So this is a less timeconsuming process to test if new versions work or not..