How do I install a NuGet package into the second project in a solution?

I'm currently working on a solution that initially contained one project (My.First.Project.Name). I've installed Castle Windsor by executing:

Install-Package Castle.Windsor

I've just added another project (My.Second.Project.Name) to the solution and want to install Castle Windsor into this project also, but when I run Install-Package Castle.Windsor again, I get the error:

> 'Castle.Core 2.5.2' already installed
> 'Castle.Windsor 2.5.2' already installed
> My.First.Project.Name already has a reference to 'Castle.Core 2.5.2'
> My.First.Project.Name already has a reference to 'Castle.Windsor 2.5.2'

So my question is: How do I persuade the NuGet Package Manager to install the package into the second project?

There's 3 approaches :).
In NuGet 1.1 (The latest release) we've improved powershell pipelining so you can do this:

Get-Project -All | Install-Package SomePackage

That will install "SomePackage" into all of your projects. You can use wildcards to narrow down which projects:

Get-Project Mvc* | Install-Package SomePackage

That will use wildcard semantics (in this case, find all projects that start with mvc).

Get-Project SomeProject | Install-Package SomePackage

That will install SomePackage into SomeProject and nothing else.

There's two approaches.

As you already learned, the Package Manager Console has a drop down that lists the projects in your solution.

The other approach is to use the -Project flag. Nice thing about that is it gives you Intellisense with the project names! For example:

Install-Package SomePackage -Project MvcApplication2

The answer is, embarassingly, blindlingly simple.

The "Package Manager Console" has a drop-down titled "Default Project" in its toolbar, changing the project there to My.Second.Project.Name then allows Install-Package Castle.Windsor to install the package into the second project.

In Visual Studio 2015 (as of Nuget v3.1.2) the syntax is now:

Install-Package ThePackage -ProjectName YourProjectName

Note: -ProjectName vs -Project

In Visual Studio, you can go to Tools -> NuGet Package Manager -> Manage NuGet Packages for the entire Solution. From there, select the Nuget Package you want to share between projects and click Manage. This will allow you to add a specific installed NuGet Package to whichever other projects you want.

If you just need to copy packages from existing project to the new one, just copy and/or modify packages.config file to the new project and run Update-Package -reinstall -Project YourProjectName

There is also the option to force a reinstall. With certain problems, this helped me.

Update-Package Microsoft.Owin -Reinstall