What happens if you run C:\Program files\Alwil Software\Avast4\ashSimpl.exe ?

Where, on the Simple User Interface (skin) or on the Splash Screen?
Can you use the special key of ‘context menu’ in your keybord (right side of the space bar)

Again, what do you mean? The Simple User Interface or the ‘Introdutory Help’?

These are the settings of the providers I suppose…

No, you do not lose anything… I don’t think the problem is related to avast really…
What is the language of your setup.exe file (the file you download to install avast)?