Upgrade Visual Studio 2013 solutions to Visual Studio 2015 - visual-studio

Question

I have installed both Visual Studio 2013 and Visual Studio 2015. Projects and solutions that were created in VS2013 are opened by VS2013 as I would expect, but I would like to be able to upgrade those files so that they would be opened by VS2015 when double clicked.
How can I upgrade solution files that are in VS2013 format so that the Microsoft Visual Studio Version Selector will open them in VS2015?

Answer 1

The simplest solution IMO (also worked for 2012 and 2013) is:
Open the solution file using Visual Studio 2015
Select the solution file in Solution Explorer
Select File / Save MySolution.sln As...
Overwrite the existing solution file.

Answer 2

Change the version in the .sln file
# Visual Studio 2013
VisualStudioVersion = 12.0.31101.0
To match whatever version you have
As of this morning my VS Enterprise is 14.0.23107.0
Example:
# Visual Studio 2015
VisualStudioVersion = 14.0.23107.0
Visual Studio 2015 Update 3 is 14.0.25420.1

Answer 3

Note: This works for VS 2015 and 2017
An alternative to hand-editing the .sln file or re-saving on top of the original .sln file:
Open the solution in Visual Studio
Right click solution > Add > New Solution Folder (name does not matter)
Save solution
Delete the newly added solution folder
Save solution
The solution will now be upgraded.

Answer 4

I ran across this looking for the same thing. The accepted answer works, but I noticed some comments about not being batchable. I found an option for batching and I thought I'd share.
You can use the /upgrade option in devenv.com. This means it's batchable. For example, to recurse the current directory upgrading all .sln files (after backing them up), you could do this:
dir -Recurse -path ".\" *.sln | ForEach-object {
Copy-Item $_.FullName "$($_.DirectoryName)\$($_.Name.Remove($_.Name.Length - $_.Extension.Length)).vs2013$($_.Extension)";
& "C:\Program Files (x86)\Microsoft Visual Studio 14.0\Common7\IDE\devenv.com" /upgrade $_.FullName
}

Answer 5

I solved the problem by this: Right click on solution, "Retarget solution".(vs2013)

Answer 6

The other solutions here didn't work for me. My project was created in Visual Studio 2012, and I am now using Visual Studio 2015, but this should work if you're going from 2013 to 2015. This is how you manually upgrade a project from a earlier version to a newer one:
Open the Developer Command Prompt for VS2015 (to find it: https://msdn.microsoft.com/en-us/library/ms229859(v=vs.110).aspx)
Type in devenv SolutionFile | ProjectFile /upgrade and press enter
Where SolutionFile | ProjectFile is the full path with filename of your .sln file.
https://msdn.microsoft.com/en-us/library/w15a82ay.aspx