Because Visual Studio 2012 is a legacy product, you will not find the preparation executable on Microsoft’s primary download pages anymore. However, official, digitally signed copies are still available via:
This error appears if no base installation of Visual Studio 2012 is detected. Update 5 is purely an update, not a standalone product. visual studio 2012 update 5 preparation.exe
Not a standard Microsoft file; treat as potentially suspicious unless proven otherwise. Because Visual Studio 2012 is a legacy product,
Microsoft’s official Update 5 for Visual Studio 2012 was typically named: visual studio 2012 update 5 preparation.exe
feature. This allows local workspaces to be updated automatically after a project is renamed in Team Foundation Server 2015. Microsoft Support System Requirements