Yesterday afternoon I had to start a full re-installation of a CRM 2011 server due to missing product key to upgrade from trail version to production server license. The trail server had installed rollup 10 v2 with English database language and Norwegian language package. The installation media provided by the customer was the RTM version, and I need to install this and first install the Rollup 6 before applying the Rollup 10 v2. When this was completed, I could reimport the old organization database.
In addition, Pablo Peralta has good step-by-step post on how to install a CRM 2011 server On-premise.