This is an interesting issue and definitely a compatibility issue. Have either of you attempted to uninstall salesforce? Simple deleting the folders does not remove it form your system, you will need to uninstall it.

Let me know as i never used sales force and constant contact works for me on Outlook 2010 using Exchange 2010.

Yes! I uninstalled Salesforce a year ago and also tried to delete the remaining entries of Salesforce in the registry.

I have no idea, where I can find find the remaining parts, which could be the cause for the described effect.

The installer of Business Contact Manager must find some remains of the uninstalled Salesforce and starts the installation of the Salesforce Outlook-Add in instead of the Business Contact Manager.