Disclaimer: This is as is, I cannot guarantee that this will even work and that it will not fubar your VS installation.
In the case of the Enterprise Library it only works currently with VS 2010. Luckily for me one of the Microsoft support engineers offered up a solution and steps to solve this predicament (my dev system only have VS 2012 now).
- Open up the vsix file you will to up by doing the following in this example we will use Microsoft.Practices.EnterpriseLibrary.ConfigConsole.vsix
- right click the file
- mouse over 7-zip
- click open archive
- right click on the extension.vsix
- click edit
- Find the following line
<SupportedProducts> <VisualStudio Version="10.0"> <Edition>Pro</Edition> </VisualStudio> </SupportedProducts>
- Change it to this
</VisualStudio> <VisualStudio Version=“11.0”> <Edition>Pro</Edition> </VisualStudio> </SupportedProducts>
- Close out of the manifest
- Install the vsix and Visual Studio 2012 should now be available.