How do I get Visual Studio to recognize my environment variables?

For example, suppose you have the following in one of your .CSPROJ project files:

		 <Import Project="$(INETROOT)\private\target\MyCustomBuildSteps.targets" />
	

, where INETROOT is supposed to be an environment variable.

In this situation, Visual Studio will refuse to even load the project file if ""MyCustomBuildSteps.targets"" cannot be found. This means that the INETROOT environment variable must be set appropriately in the context of the Visual Studio process. There are really two ways to do this:

1. ""Set INETROOT as a session-wide environment variable by using Control Panel or the equivalent registry keys at HKEYCURRENTUSER\Environment or HKEYLOCALMACHINE\SYSTEM\CurrentControlSet\Control\Session Manager\Environment""
2. If INETROOT is set via some batch script that gets run only in a special command window (such as Razzle, for example), then you must launch VS from that same command window.

There is a way to allow Visual Studio to at least load the project file, even if INETROOT is not set within the context of the Visual Studio process. You can put something like this into your project file :

		 <Error Condition="'$(INETROOT)'==''"
		        Text="The &quot;INETROOT&quot; property is not set in project &quot;$(MSBuildProjectFile)&quot;.
		              Please invoke the IDE or build environment from a CoreXT enlistment window."/>
	

		 <Import Condition="'$(INETROOT)'!=''" Project="$(INETROOT)\private\target\MyCustomBuildSteps.targets" />
	

This works because only the <Import> tag is processed at project-load time, and if INETROOT is not set, then the <Import> is ignored. But in that case, if you try to do a Build, you'll get an immediate build failure due to the <Error> tag.