I work in a team on a Visual C++ project. Following advice we got we're tracking the project's .sln file with our SCM. It turns out that each time I pull from my partner (yes, we use git) and open the solution in VS, the .sln file is updated. The part being updated is the long id that appears several times (in this case ending with 7C44) in the following segment:
{828CB89E-F092-3B7A-2F8C-62E146587C44}.Debug|Win32.ActiveCfg = Debug|Win32
{828CB89E-F092-3B7A-2F8C-62E146587C44}.Debug|Win32.Build.0 = Debug|Win32
{828CB89E-F092-3B7A-2F8C-62E146587C44}.DebugStaticCRT|Win32.ActiveCfg = DebugStaticCRT|Win32
{828CB89E-F092-3B7A-2F8C-62E146587C44}.DebugStaticCRT|Win32.Build.0 = DebugStaticCRT|Win32
{828CB89E-F092-3B7A-2F8C-62E146587C44}.Release|Win32.ActiveCfg = Release|Win32
{828CB89E-F092-3B7A-2F8C-62E146587C44}.Release|Win32.Build.0 = Release|Win32
{828CB89E-F092-3B7A-2F8C-62E146587C44}.ReleaseStaticCRT|Win32.ActiveCfg = ReleaseStaticCRT|Win32
{828CB89E-F092-3B7A-2F8C-62E146587C44}.ReleaseStaticCRT|Win32.Build.0 = ReleaseStaticCRT|Win32
{828CB89E-F092-3B7A-2F8C-62E146587C44}.Template|Win32.ActiveCfg = Template|Win32
{828CB89E-F092-3B7A-2F8C-62E146587C44}.Template|Win32.Build.0 = Template|Win32
What does this number mean? How can we make it stop changing between us?
That is a GUID which Visual Studio uses to refer to the individual projects. You will find the same GUID at the top of the .sln file, where the projects are defined/imported.
Visual Studio reads the GUID from the corresponding .csproj/.vbproj file. There you should find a ProjectGuid property near the top with the corresponding GUID. If you and your partner have a different GUID defined there, the .sln will also update.