How to upgrade InfoPath 2010 automatically to new template

Unfortunately there is no way to avoid the InfoPath 2010 users getting that prompt to “Save and Update Form”. 

Even with code it is not possible. 

The users will only get the prompt the initial time to Save and Update Form as you already know, and then any subsequent openings will not prompt the users for any updates. 

The only way around this option is to have the InfoPath 2010 users clear their InfoPath cache first, before accessing the forms. 

This will delete the currently saved template information that is in their cache, so it will not prompt them to save and update the form since it doesn’t have any record of there being an open form.

The way to have users empty their InfoPath cache is by doing this: 

Have them go to Start then either launch “Run” or in their “Start Search” bar (right above the Start button) have them type the following command: 

InfoPath /cache clearall 

(this will launch the InfoPath client on the user’s machine and they will now have empty InfoPath cache)