Outlook 2003 on Windows Vista dialogue box when opening attachments

If you are getting a dialogue box in Microsoft Outlook 2003 installed on Windows Vista saying "You should only open attachments from a trustworthy source ...", every time you open a PDF or other attachment, this is caused by a rights issue between Office and Vista.

The problem is that Outlook 2003 cannot make the change needed to save your choice when you uncheck the option to prompt you every time.

Navigate to C:\Program Files\Microsoft Office\OFFICE11 and right click on Outlook.exe. Choose Run as administrator. Now open an attachment, uncheck the box, and the setting will be saved.

You should be good to go!