You experience the following issues on a computer that's running Windows RT 8.1, Windows 8.1, or Windows Server 2012 R2.
Issue 1When you intentionally type an acronym in uppercase letters, the auto-correct feature incorrectly changes the case of the characters.
Issue 2The first character after the first period is capitalized automatically and unexpectedly. For example, when you type xxxxx.com in Mail app, the auto-correct feature changes this to xxxxx.Com.
To resolve this issue, install update 2919355. For more information about how to obtain update 2919355, click the following article number to view the article in the Microsoft Knowledge Base:
2919355 Windows RT 8.1, Windows 8.1, and Windows Server 2012 R2 Update April, 2014
Microsoft has confirmed that this is a problem in the Microsoft products that are listed in the "Applies to" section.
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