Protected view is a new security feature for all Office documents which arrive in email or are downloaded from Internet sources. This is a security sandbox used by Office 2010 to enhance attachment security. Administrators will be able to control whether all email attachments or only those from outside their Exchange network use Protected view.
How it works: When an emailed (or downloaded) document is opened, a red band appears at the top of the document to alert the user that the document is in protected view and cannot be edited. If the user trusts the document, they click the Enable editing button to begin editing. All attachments are read-only.
When a document that was previously attached to an email (or downloaded from the Internet) is opened, the red message bar states "This file originated as an email attachment " or "This file was downloaded from the Internet". The application knows this because Windows uses the Attachment Execution Service to place a zone identifier in an alternate data stream of the file which indicates it was downloaded from the Internet Zone. When Word, Excel, or PowerPoint opens the file and sees this marker it knows to open the file within Protected View and the user sees the red bar.
This setting opens all Office documents in a read-only state and you need to click a button before you can edit the document. (To save the document, you'll need to use Save as - see "Edit and Save Outlook's Read-Only Attachments" if you want to save documents back to the email message.)
To change the Protected view setting, you need to make the change in each Office application.
Go to the File, Options Trust Center dialog and select Protected View. Disable the option to enable it for Outlook attachments. (You may also want to disable it for files originating from the Internet.)
Once you do this, you'll get the Open/Save dialog, which can be disabled by editing the registry. The instructions to do this are below.
Note: I recommend making this change only for the document types you open often.
In each of the following keys, add or edit the EditFlags binary value so the value is 00 00 01 00
Or use our prepared reg file that sets the EditFlags value for Word (docx, doc), Excel (xlxs, xls) and Powerpoint (ppts, ppt) files.
EditFlags for Word, Excel, and Powerpoint
For more information, see Restore (or Hide) the Open Save Dialog