Symptoms
When you create a virtual desktop on Windows 8.1 or Windows Server 2012 R2, you expect mouse actions to work similarly to how they work in earlier versions of Windows. However, mouse actions may be blocked. For example, clicking the mouse pointer does not stop the installation process when you create a new virtual desktop.
Cause
This problem occurs because the mouse hooks are invoked across desktops.
Resolution
Update information
The fix for this problem is included in security update 3002885. This update is dated November 11, 2014.
Status
Microsoft has confirmed that this is a problem in the Microsoft products that are listed in the "Applies to" section.
References
Learn about the terminology that Microsoft uses to describe software updates.