MDT automatically uninstalls previous versions of MDT and BDD before installing MDT, including the following versions:
· Previous versions of MDT 2012
· MDT 2010 Update 1
· MDT 2010
· MDT 2008 Update 1
· BDD 2007 Update 2
In addition to upgrading the MDT installation, upgrade any existing MDT 2012 deployment shares, MDT 2010 deployment shares, MDT 2008 deployment shares, and BDD 2007 deployment shares. For more information on this process, see Upgrade an Existing Deployment Share in the Deployment Workbench.