Office File Validation is a feature that performs security checks on files. If Office File Validation detects a problem with a file, the file cannot be opened.
A trusted location is a folder on your computer or on a network. Any file that you put in a trusted location can be opened without being checked by the Trust Center. Additionally, the file is not opened in Protected View.
Files from the Internet and from other potentially unsafe locations may contain viruses, worms, or other kinds of malware. These agents may harm your computer. To help protect your computer, Office 2010 opens files from these potentially unsafe locations in Protected View. By using Protected View, you can read a file and inspect its contents. Additionally, you can reduce the risks that are associated with the actions that are mentioned in the “Symptoms” section.
For more information about trusted locations, visit the following Microsoft Web site:
Add, remove, or modify a trusted location for your files