Visual Studio 2010: The specified module could not be found. (Exception from HRESULT:0x8007007E)

Update: After the Windows 8 Release, this article became one of the top reads! This is mainly because you probably installed Visual Studio 2012 then realized that it broke your 2010. This is something even Microsoft support does not readily know!

Symptom:

• You have installed Visual Studio 2012 recently while having Visual Studio 2010 SP 1
• You then open the Servers and connect to an SQL server (either 2008 or 2012) from VS 2010
• Try to create a table in one of the connected database.
• You get an error "The specified module could not be found. (Exception from HRESULT:0x8007007E)"
• Additionally if you want to design the DBML with LINQ to SQL, you cannot drag a table into the Design Surface

Cause

When you installed VS 2012 it has "corrupted" with the following DLL version that does not work right in VS 2010.

C:\Program Files (x86)\Common Files\microsoft shared\Visual Database Tools\dsref80.dll

Fix:

Note that "repair" of Visual Studio will not work. Do not go down that path! You pretty much need a completely clean installation of this, as it is in the shared file. So do not waste your time.

Instead...

Find a system that never had a Visual Studio 2012. Harvest dsfre80.dll  and copy this to the same location on your damaged computer and you are good to go.

At worst case, create a Virtual Machine, for example use the free Virtual Box, install a VS 2010 on it and harvest the file.