Preventing Changes to Form Templates
InfoPath both designs and displays forms. Only members of the Web Designer or Administrative groups can create form libraries or change the InfoPath form template used by the library. However, templates deployed to clients can be changed. In most cases, you won't want members opening those templates in Design mode and tinkering with them. There are two approaches to solving this problem:
Enable form protection. This approach discourages members from changing form templates, but does not prevent them from doing so.
Disable Design mode on members' systems. This approach keeps users from changing existing form templates and prevents them from creating new ones.
To protect a template from changes:
Open the template in Design mode.
Choose Tools → Form Options → Advanced, select "Enable protection," and click OK.
Protected templates display a warning if the user opens them in Design mode. That's weak protection at best, but if you sign the protected template with a digital signature, you can both discourage changes and detect them if they are made (changes overwrite the digital signature, so the template will no longer be trusted).
A stronger solution prevents users from designing any templates. You can use the Custom Installation Wizard (CIW) to create a customized setup program for Office that omits the design features from InfoPath. In order to do that:
Run the CIW.
Open the InfoPath Windows Installer file (INF12.msi).
Configure Disable InfoPath Designer ...