Windows Server 2012 R2 Update

Microsoft released Windows Server 2012 R2 Update at BUILD conference.
Windows Server 2012 R2 Update doesn't have any new features, but includes cumulative roll-up, bug fixes and a range of enhancements,such as EMIE, AD fix for Office 365 and UI enhancements.

"After the update is installed, the following features are present:

• Internet Explorer 11 now includes an “Enterprise Mode.” This mode is available if you disable Enhanced Security Configuration and provides better compatibility for sites designed for Internet Explorer 8, along with tools to manage which web apps use it. You can specify a list of web apps to render dynamically in Enterprise Mode, avoiding compatibility problems with web apps written for older versions of Internet Explorer. For more information, see the Internet Explorer 11 FAQ for IT Pros or TechNet documentation.
• The user interface includes buttons for Search and Power on the Start page. If you install the Desktop Experience feature, other changes introduced with Windows 8.1 Update will also be visible. For details, see What's new in Windows 8.1 Update and Windows RT 8.1 Update. The specific Windows 8.1 features installed when you install Desktop Experience have not changed from those in Windows Server 2012 R2 (seeDesktop Experience Overview).
• Active Directory Federation Services (AD FS) has added the capability for an administrator to enable signing in with an alternate login ID that is an attribute of the user object in Active Directory Domain Services (AD DS). This enables customers to adopt Azure Active Directory without modifying on-premises User Principal Names (UPNs). It also allows users to log in to the computer using an Office 365 email address instead of a UPN. This change does not affect the Active Directory schema. For more information, see Configuring Alternate Login ID.
• The update includes all other updates released since Windows Server 2012 R2 was released."

Release notes, system requirements, deprecated features, and related release documentation for Windows Server 2012 R2 also apply to Windows Server 2012 R2 Update. See Install and Deploy Windows Server 2012 R2 and Windows Server 2012 for those topics.

Microsoft suggests running Msinfo32.exe to confirm the update's installation. It should report a hardware abstraction layer of "6.3.9600.17031," if successful.

Updates included in cumulative roll-up:
http://support.microsoft.com/kb/2919442 http://support.microsoft.com/kb/2919355
http://support.microsoft.com/kb/2932046
http://support.microsoft.com/kb/2937592
http://support.microsoft.com/kb/2938439
http://support.microsoft.com/kb/2949621

Related Information:

Microsoft's Windows 8.1 updates also tweak Windows Server 2012  The Register
Windows Server 2012 R2 Update - Notes from the lab  Deployment Research
Security baselines for Windows 8.1, Windows Server 2012 R2 and Internet Explorer 11  TechNet
Hyper-V: Update List for Windows Server 2012 R2  Wiki
What's in Windows Server 2012 R2 Update 1?  WindowsITPro
Windows 8.1 and Windows Server 2012 R2 Users Face New Upgrade Pressures  RedmondMagazin
Notes on the Windows 8.1 Update for Windows Server 2012 R2  The Expta Blog
Windows RT, Windows 8, and Windows Server 2012 update rollup: April 2014  MSFT Support

Edge Show 97 - Generation 2 Virtual Machines in Windows Server 2012 R2:
In this episode Symon interviews John Howard, a Senior Program Manager on the Hyper-V Team, to discuss the features and benefits of Generation 2 Virtual Machines in Windows Server 2012 R2.  Generation 2 Virtual Machines offer a variety of security and configuration benefits, taking advantage of the latest advances in hardware and driver virtualization.

Edge Show 97 - Generation 2 Virtual Machines in Windows Server 2012 R2: