but where do you select the old database ? there not a single field for settings?...
That's two different stories. If you want to migrate data and images from the old tables into the new VM2 tables, use 'Tools & Migration' - 'Migration* tab.
Use 'Sync Media' if you want to synchronize already existing image files, which are located in the image directories specified in VM2 'Configuration' - 'Templates' - 'Media File Settings' (that's where the image paths are being set in the latest VM2 SVN version), so that VirtueMart 2 recognizes images which you copied or migrated into these image directories.