VS2013 Ultimate - an exception popup window occured when launching

I installed VS 2013 Ultimate on my machine, then ran some updates . Now when I launching the VS 2013, always got an exception popup window.  check the AppData\Roaming\Microsoft\VisualStudio\12.0\ActivityLog.xml

I saw this error

<entry>
    <record>733</record>
    <time>2014/12/09 23:12:43.765</time>
    <type>Error</type>
    <source>Extension Manager</source>
    <description>Extension will not be loaded because an extension with the same ID &apos;Microsoft.Windows.DevelopmentKit.Desktop&apos; is already loaded at C:\PROGRAM FILES (X86)\COMMON FILES\MICROSOFT\EXTENSIONMANAGER\EXTENSIONS\MICROSOFT\WINDOWS KITS\8.0\DESKTOP SDK\...</description>
    <path>C:\PROGRAM FILES (X86)\COMMON FILES\MICROSOFT\EXTENSIONMANAGER\EXTENSIONS\MICROSOFT\WINDOWS KITS\8.1\DESKTOP SDK\</path>
  </entry>

I have both VS 2012 and 2013 installed on my desktop.

C:\PROGRAM FILES (X86)\COMMON FILES\MICROSOFT\EXTENSIONMANAGER\EXTENSIONS\MICROSOFT\WINDOWS KITS\8.0\DESKTOP SDK\...
C:\PROGRAM FILES (X86)\COMMON FILES\MICROSOFT\EXTENSIONMANAGER\EXTENSIONS\MICROSOFT\WINDOWS KITS\8.1\DESKTOP SDK\

Can someone give me some idea how to resolve this issue?

Thanks,

-Ying Ren