Did you try without creating a DB first?

Also, instead of doing it through the interface, click Script on this interface and then run it from the script (you can post it here for inspection as well).

>I am trying to move a SQLExpress2008R2 DB to SQLExpress2012.
>
>I a full backup of the SQL Express2008R2 DB. I then created a DB in SQLExpress2012 with the same name. Attempting to Restore the SQL2008 DB to the SQLExpress2012 DB generated the following security error. What am I missing here?
>
>
>TITLE: Microsoft SQL Server Management Studio
>------------------------------
>
>Restore of database 'Lepton' failed. (Microsoft.SqlServer.Management.RelationalEngineTasks)
>
>------------------------------
>ADDITIONAL INFORMATION:
>
>System.Data.SqlClient.SqlError: The operating system returned the error '5(Access is denied.)' while attempting 'RestoreContainer::ValidateTargetForCreation' on 'c:\Program Files\Microsoft SQL Server\MSSQL10_50.SQLEXPRESS2008R2\MSSQL\DATA\Lepton.mdf'. (Microsoft.SqlServer.SmoExtended)
>
>For help, click: http://go.microsoft.com/fwlink?ProdName=Microsoft+SQL+Server&ProdVer=11.0.3000.0+((SQL11_PCU_Main).121019-1325+)&LinkId=20476