If the event viewer shows no errors, it means it is just a slow load up of a program. The only way I know how to determine is to do a clean boot or a diagnostic startup using msconfig; but that is essentially the same as clean boot from where you are.
My first test to determine a problem program is clean boot. I of course would not push the issue because if something did go wrong at this point, I would feel awful. My only suggestion is wait for others to come, by. I hope they do for your sake and I will learn something new, too.
Edit: Turn off your antivirus that often causes these type of problems, see how that goes.
Fill out your system specs. Dont know them use this
http://www.piriform.com/speccy