I couldn't find the topic asking the question if the Vatican Museum was free during Cultural Week. I found this on the Yahoo/answers that may help the poster.
the program of the culture week is normally posted on the web site of the Ministero dei Beni Culturali, but it is not yet available. you can check the following page for updates http://www.beniculturali.it/sala/dettagl...
as for the vatican museums they are not free in the culture week as they belong to the vatican and not to italy. the vatican museums are normally open mo thru sat (ticket € 13,00) and, for free, on the last sunday of each month (next free opening will be march 30). this is the link to the vatican museums web site: http://mv.vatican.va/3_EN/pages/MV_Home....