How do I backup the configuration in case of a computer crash? Is there a backup Utility or do I just backup the show files?
You only need to backup the show files. You can set up a different location for the Autobackup files in the User Preferences. Doing this makes it possible to backup to a USB stick.
Additionally, if you have custom fixture profiles, custom effect templates, user interface themes, or other custom user data, you may want to make a copy of that as well. I don’t think that all of that data is stored in the showfile (I may be wrong though).
To do so, locate your Vista User Data folder (usually something like ~/Documents/Vista 3, just depends on what you set up when installing Vista) and make backup copies of any data that might be important in that folder.
Just wanted to that point out in case you have custom fixture profiles, etc. and want to back that data up.