Where is the SQL Server 2008 R2 Installation Media director? This question asks during a 'new installation or add features to an existing installation'. The installation media root directory is not indicated under 'options'. I trying side-by-side installation next to SQL Server 2008 Express Edition.
It appears that C:\Program Files\Microsoft SQL Server\100\Setup Bootstrap\SQLServer2008R2 (where 1033_ENU_LP, Resources, and x86 dirs are installed) is the installation media root directory, but is is not a valid folder.
Also tried copying the 1033_ENU_LP, Resources, and x86 dirs from the C:\Program Files\Microsoft SQL Server\100\Setup Bootstrap\SQLServer2008R2 into a directory that I created in c:\2008R2installationDir, and then running setup.exe, but still do not have an installation media root dir specified under options.