Upgrade Visual Studio 2013 solutions to Visual Studio 2015

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?

The simplest solution IMO (also worked for 2012 and 2013) is:

1. Open the solution file using Visual Studio 2015
2. Select the solution file in Solution Explorer
3. Select File / Save MySolution.sln As...
4. Overwrite the existing solution file.

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

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:

1. Open the solution in Visual Studio
2. Right click solution > Add > New Solution Folder (name does not matter)
3. Save solution
4. Delete the newly added solution folder
5. Save solution

The solution will now be upgraded.

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
}

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

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:

1. Open the Developer Command Prompt for VS2015 (to find it: https://msdn.microsoft.com/en-us/library/ms229859(v=vs.110).aspx)
2. 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