This is a very good blog post about troubleshooting startup performance issues for Visual Studio:
http://startbigthinksmall.wordpress.com/2011/11/08/activity-log-profiler-find-out-which-extension-is-slowing-down-your-visual-studio/
In summary, start VS with the /log flag:
"C:\Program Files (x86)\Microsoft Visual Studio 11.0\Common7\IDE\devenv.exe" /log
(11.0 is for VS 2012, will need to be different for other versions of course).
Also download this xsl file:
https://github.com/lcorneliussen/ActivityLogProfiler/raw/master/ActivityLogProfiler.xsl
and place it into folder:
%AppData%\Roaming\Microsoft\VisualStudio\xx.x (version number)
Then delete the original xsl file ActivityLog.xsl, and make a copy of the downloaded xsl file, then rename that copy as the original (ActivityLog.xsl). We want to keep a copy of the downloaded one, because each VS startup overwrites the .xsl....
Then open the ActivityLog.xml file with internet explorer and examine the startup information.
