Prior to version 2010 of Measurement Studio, Measurement Studio did not support activation through NI License Manager. So in this case to upgrade from an evaluation version to a fully licensed version, you must reinstall Measurement Studio. This has been resolved with NI License Manager support in 2010 and later. More details here: http://digital.ni.com/public.nsf/allkb/797A837B7A0EECDC8625752E00775ACE?OpenDocument
Additionally, when you purchase a National Instruments license, the serial number you receive is valid for that version and all previous versions of the product. So you can use your Measurement Studio 2010 SP1 serial number for Measurement Studio 2009.
National Instruments
