I've downloaded from the partner sites (given on NI website) parts and footprints models for Multisim 10 and Utilboard 10. Where (with path) should I place those files to be visible in the both mentioned programs ?
This depends on the file format of the footprints and models. If they are PRZ files, you can import them by just by opening them in Windows. An import utility should come up and guide you through the import process. You will have the option of importing the data into your corporate or user database.
If they are not PRZ files, let us know and we will direct you in the right direction.
To import the footprints to Ultiboard, try the following: