Applies ToWindows 8.1 Enterprise Windows 8.1 Windows 8.1 Pro Windows RT 8.1 Windows Server 2012 R2 Datacenter Windows Server 2012 R2 Essentials Windows Server 2012 R2 Foundation Windows Server 2012 R2 Standard

This compatibility update is a software update that improves the compatibility experience in Windows RT 8.1, Windows 8.1, and Windows Server 2012 R2. Microsoft regularly releases Windows compatibility updates to improve the overall user experience. This compatibility update is dated May 2014.

More Information

Update information

How to obtain this update

Windows UpdateThis update is available from Windows Update.

Microsoft Download Center

The following files are available for download from the Microsoft Download Center:

Operating system

Update

All supported x86-based versions of Windows 8.1

Download Download the update package now.

All supported x64-based versions of Windows 8.1

Download Download the update package now.

All supported x64-based versions of Windows Server 2012 R2

Download Download the update package now.

For more information about how to download Microsoft support files, click the following article number to view the article in the Microsoft Knowledge Base:

119591 How to obtain Microsoft support files from online services Microsoft scanned this file for viruses. Microsoft used the most current virus-detection software that was available on the date that the file was posted. The file is stored on security-enhanced servers that help prevent any unauthorized changes to the file.

The kinds of problems that are resolved by application compatibility updates

When you try to install and run certain games or applications in Windows RT 8.1, Windows 8.1, or Windows Server 2012 R2, you may experience one or more of the following symptoms:

  • The game, the application, or the driver is installed incorrectly.

  • The game, the application, or the driver causes system instability.

  • The primary functions of the game, the application, or the firmware works incorrectly.

Improvements in the compatibility experience

Applications or devices that experience a change in behavior after you install this update

The following table lists the applications and devices that were included in this cumulative update package. This table also describes the behavior of these applications and devices after you install the update.Compatibility updates trigger several changes in Windows RT 8.1, Windows 8.1, and Windows Server 2012 R2. The following are the most common.

Hard block

This prevents an application that is incompatible with Windows RT 8.1, Windows 8.1, or Windows Server 2012 R2 from running on the system.Note Microsoft enables Windows to put a hard block on a non-Microsoft application only if the manufacturer is notified.

Soft block

This notifies you when a primary function of the application may not work or may cause application instability.

Driver block

This may block an existing driver on your computer. When the driver is migrated during the upgrade, an Inbox driver will be installed.

Applications and devices that are included in this update

Applications or Devices

Version

Behavior after you install the update

Marcrium Reflect

Up to 5.0.*

Blocks application installation.

MG25-Terran2+G USB 3.0 HDD

not available

Improves user experience.

The global version of this update installs files that have the attributes that are listed in the following tables. The dates and the times for these files are listed in Coordinated Universal Time (UTC). The dates and the times for these files on your local computer are displayed in your local time together with your current daylight saving time (DST) bias. Additionally, the dates and the times may change when you perform certain operations on the files.The MANIFEST files (.manifest) and the MUM files (.mum) that are installed for each environment are listed separately in the "Additional file information for Windows RT 8.1, Windows 8.1, and Windows Server 2012 R2" section. MUM, MANIFEST, and the associated security catalog (.cat) files, are very important to maintain the state of the updated components. The security catalog files, for which the attributes are not listed, are signed with a Microsoft digital signature.

For Windows RT 8.1

File name

File version

File size

Date

Time

Platform

Acspecfc.dll

6.3.9600.16427

9,728

12-Oct-2013

21:13

Not applicable

For all supported x86-based versions of Windows 8.1

File name

File version

File size

Date

Time

Platform

Acres.dll

6.3.9600.16384

310,784

22-Aug-2013

04:16

x86

Sysmain.sdb

Not applicable

3,835,136

18-Apr-2014

02:47

Not applicable

Msimain.sdb

Not applicable

2,727,022

18-Apr-2014

02:47

Not applicable

Acgenral.dll

6.3.9600.17098

2,441,216

18-Apr-2014

09:14

x86

Drvmain.sdb

Not applicable

118,472

18-Apr-2014

02:47

Not applicable

For all supported x64-based versions of Windows 8.1 and of Windows Server 2012 R2

File name

File version

File size

Date

Time

Platform

Sysmain.sdb

Not applicable

433,638

18-Apr-2014

02:43

Not applicable

Msimain.sdb

Not applicable

2,757,398

18-Apr-2014

02:43

Not applicable

Drvmain.sdb

Not applicable

119,762

18-Apr-2014

02:43

Not applicable

Acres.dll

6.3.9600.16384

310,784

22-Aug-2013

04:16

x86

Sysmain.sdb

Not applicable

3,835,136

18-Apr-2014

02:47

Not applicable

Acgenral.dll

6.3.9600.17098

2,441,216

18-Apr-2014

09:14

x86

For more information about software update terminology, click the following article number to view the article in the Microsoft Knowledge Base:

824684 Description of the standard terminology that is used to describe Microsoft software updates

Additional file information

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