Following Moosipher's advice in this thread
, I checked C:\Program Files (x86)\Common Files\microsoft shared\Visual Database Tools.
Sure enough, there was a Visual Studio 2012 DLL in there.
(pay no attention to the file name, I've changed it so I can copy the 2010 one in).
I searched the drive for another file with the same name and in C:\Windows\Installer\$PatchCache$\Managed\34742F951AE254A38B2CE6E0E170F88A\10.0.30319, windows found a file called FL_dsref80_dll_101364_101364_x86_ln.3643236F_FC70_11D3_A536_0090278A1BB8.
So, I copied that into, C:\Program Files (x86)\Common Files\microsoft shared\Visual Database Tools, renamed it to dsref80.dll.
Checked properties and it shows 2010.
Unfortunately, this hasn't resolved the problem...
I restarted VS2010, opened my project and the same issue remains, created a new project and created a new form, DB, etc... and this behavior hasn't changed.
Still get the "database file created by earlier version of SQL Server Compact..."
And just FYI, I launched Visual Studio 2012 was was able to successfully complete this project and see my data, though the menus are a little different (add data source is under 'Project' instead of 'Data').
I'm thinking this must be the issue....
In Database Explorer, I right-click on Data Connectsion, add connection and... SQL Server Compact 4.0 isn't an option.