Q. What are the new features in Server Core in Windows Server 2008 R2?

A subset of .NET 2.0 with the components that could be implemented without too many OS dependencies. The subset doesn't include namespaces such as Ink, Stylus, Windows Themes, Mobile, Media, Speech and Visual Basic 6 compatibility.

ASP.NET with features that align with the .NET 2.0 subset.

A .NET 3.0 subset, including Windows Communication Foundation.

A .NET 3.5 subset, including Work Flow and LINQ (but no Windows Presentation Framework)

PowerShell with Server Manager cmdlets (which allow you to add and remove PowerShell components) and Best Practice Analyzer cmdlets.

Certificate Server role.

File Server Resource Manager (FSRM) File Services role.

Server Core can now be managed remotely with the IIS MMC snap-in. This isn't possible in Windows 2008 because the IIS management uses .NET, which wasn't present in Windows 2008 server core.

Windows on Windows 64 (WoW64) is an optional feature. WoW64 allows 32-bit applications to run on a 64-bit server. This is a set of binaries that has a disk footprint of around 250MB. By default, WoW64 is installed, but you can remove if you're running only 64-bit applications. Note that you need WoW64 if you want to install Active Directory, Active Directory Lightweight Directory Services, or IIS on the server core instance, because these roles all depend on 32-bit. Note that from the command line, you don't have automatic dependency installation like you do in Server Manager, so you need to add the WoW64 component before trying to install these roles. If a dependency is missing, ocsetup will fail and notify you of the missing component.

Ability to delete roles and features from the server core image. This means they will no longer be available to install and can't be brought back. Note that in Server 2008, Vista, and later OSs, the files for all components, features, and roles are stored on the OS file system. (The files are in the side by side store, which has its content hard linked to system32 if a component is actually installed, as opposed to copying the file, which would use more disk space.) Because the files are kept on disk in those OSs, you don't have to insert a CD to add components. This uses up disk space but with disk space as plentiful as it is in modern computers, this was preferable to requiring media and complications with situations such as component updates when service packs are installed.In Server Core under Server 2008 R2, if you remove a component from the file system, you have to reinstall the OS to get the component back. Note that the servicing stack is aware of this removal, so even a service pack installation will not bring the component back. This is useful in specific situations where you really want to reduce footprint. A good example would be removing the .NET binaries, which saves around 500MB of disk space.

DISM command line tool. This tool has many capabilities, including the ability to install multiple features in one command, such as dism /online /enable-feature /featurename:... /featurename:...