How to fix compatibility mode error that can appear when installing Windows Phone Developer Tools or Visual Studio 2010
I have heard from a few people who tried to install the final release of the Windows Phone Developer Tools but get an installation error like the following:
Visual Studio setup cannot run in compatibility mode.
For more information see the 'Installing' section in the Visual Studio readme at http://go.microsoft.com/fwlink/?LinkID=143397.
The link in the error message points to the Visual Studio 2010 readme because this issue can affect all editions of Visual Studio 2010, including WPDT. Item 2.1.10 in that readme provides a workaround for this issue. In my past experience, that workaround has proven to be incomplete though, so here are some updated steps that usually help solve this type of error:
Click on the start menu, choose Run, type regedit and click OK.
Browse to each of the following keys and delete any value that refers to the WPDT setup program (named vm_web.exe):
HKEY_CURRENT_USER\SOFTWARE\Microsoft\Windows NT\CurrentVersion\AppCompatFlags\Compatibility Assistant\Persisted
HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows NT\CurrentVersion\AppCompatFlags\Compatibility Assistant\Persisted
If the above doesn’t help, then you can also try to save vm_web.exe to your computer and run it from there. When compatibility mode is triggered by Windows, it is based on a full path to the setup executable, so if you save it to a different location than you previously tried to run it from and then run it again, that can help avoid triggering compatibility mode.