It is not MSN Office. MSN is inetenet, and Office is the suite of
programs for office tasks. Try to reinstall office.
In fact the solution of my issues was that I had just installed Autodesk Inventor 11 witch includes "Autodesk Vault 5 For MSN office".
Ok, I just uninstalled it (Autodesk Vault 5 For MSN office)and the "slowed down" issue was resolved.
I recommend to anybody needs to works with "AUTODESK INVENTOR 11" dont install the "Vaul 5 for MSN office" feature.
So long Buddies.