Visual Studio 2012 doesn't convert vs2010 solution?

I opened my vs2010 solution with vs2012 but it didn't make any conversion as from 2008 to 2010 was happening. So my solution still remains the same as 10 label on it. when I make a new solution of course it has 11 label on it. I haven't got any problem running like that but I am curious. Is there any difference? if yes, how to convert into vs2012 solution?

I managed to 'convert' the solution file to change the line containing '# Visual Studio 2010' to '# Visual Studio 2012' in the .SLN file.

Manual editing of the solution file is not necessary, or recommended. Simply open the VS2010 solution in VS2012, left-click the solution (at the very top of the Solution Explorer), then use File | Save As to overwrite the original file. This will effectively convert the VS2010 solution file to a VS2012 solution file.

http://msdn.microsoft.com/en-us/library/hh266747(VS.110).aspx">There are some exceptions, but mostly you'll be able to open the same project and solution files files in both VS2012 and VS2010 SP1.

VS2012 may convert projects when you first open them, but the changes are (except noted in the document linked) backward compatible with VS2010 (ie using conditionals where needed to only apply to either version when loaded) Most project types will be left entirely untouched though.

It is about Visual Studio 2012 Compatibility

If you created your assets in Visual Studio 2010 with Service Pack 1 (SP1), many of them will load and run in Visual Studio 2012 without any further action on your part.

Many assets will also open again in Visual Studio 2010 with SP1 without any issues, even after you open those assets in Visual Studio 2012

For C++ projects it makes a difference, as the 2012 compiler (VC11) will only be used on projects that are explicitly 2012, not on 2010 projects opened in VS 2012. Some C++11 improvements are available with the VC11 compiler but not with VC10 (see this SO Answer for a summary), including:

• Range based for-loops
• New standard library headers (atomic, mutex, thread,...)
• Smaller standard library container sizes
• (And more to follow when the Nov 2012 CTP is delivered to VS 2012)

In order to convert from VS 2010 project to VS2012 there is no need to manually edit the solution file or 'Save As' over the existing project. Instead:

> If you decline the update when first prompted, you can update the project later by opening the Project menu and choosing Update VC++ projects... [at the top of the menu options]

From MSDN's "How to: Upgrade Visual C++ Projects to Visual Studio 2012"
(This page was linked from @Joachim's MSDN link, but I wanted to have the answer here on SO since a number of other answers suggested manual workarounds instead of this VS 2012 feature)

In my case, I had some Visual Source Safe stuff (my project was created with Visual Studio 2003/2005, yes, very old!)

Once I manually removed the VSS stuff, the conversion succeeded. PS: I know it's about VS2010, but maybe this helps others.

You can convert a project from VS2010 to VS2012 by doing the following:

1. Add the 2010 project to your VS2012 solution by right-click on your solution in the Solution Explorer and Select Add --> Existing Project...

2. The project will appear in the solution and will have (Visual Studio 2010) appended to its name.

3. Right-click on the added project and select Properties.

4. In the Configuration Properties --> General pane, change the setting in Platform Toolset field to Visual Studio 2012 (v110)

5. Repeat for each configuration type, e.g. Release and Debug.

I came across this question while googling for a solution to a specific problem: MSBuild was failing to execute the Publish target against a VS2012 solution that had started life in VS2010 when called from the command line (specifically through TeamCity):

error MSB4019: The imported project "C:\Program Files (x86)\MSBuild\Microsoft\VisualStudio\v10.0\Windows Azure Tools\2.3\Microsoft.WindowsAzure.targets" was not found. Confirm that the path in the <Import> declaration is correct, and that the file exists on disk.

MSBuild was looking for the Azure SDK 2.3 targets in the VS10 location (C:\Program Files (x86)\MSBuild\Microsoft\VisualStudio\v10.0\Windows Azure Tools\2.3\Microsoft.WindowsAzure.targets). The cause is explained by Sayed Ibrahim Hashimi in a blog post and, as I understood it, boils down to some decisions they made while enabling cross-version compatibility for solution files. The solution was simple: add the VisualStudioVersion property to the MSBuild invocation, something like this:

msbuild.exe MyAwesomeWeb.sln /p:VisualStudioVersion=11.0

Practically speaking, this overrides the following in each csproj file:

<VisualStudioVersion Condition="'$(VisualStudioVersion)' == ''">10.0</VisualStudioVersion>

Presumably you could get the same result by editing all of these by hand to replace 10.0 with 11.0 but that might break backwards-compatibility -- I haven't tried it. I also haven't tried an update to VS2013 to see if the problem persists.

So to wrap this up by answering the question: yes, there are some differences before you "convert" (using any of the methods offered by other answerers) and some differences remain afterwards.

This is slightly different, but along the same lines so in case it helps anyone:

I was loading a project where it looked like it was loading and then kept showing all projects as unavailable. No errors were on the migration report. I tried reloading the solution and projects many times, using various methods including suggestions here.

Finally I found a "Resolve Errors" option when right clicking on the solution in the Solution Explorer. VS went through a load process again and it worked; no problems.

I don't know what it did differently that time, but apparently it made a difference.

it's to simple just edit the .sol file change the version to 11

like this

Microsoft Visual Studio Solution File, Format Version 12.00

Visual Studio 2012