Today, Microsoft decided to be down-right annoying! A windows update has changed some setting or another on my Vindows Vista Ultimate and Home Premium machines that now means that an "Open File - Security Warning" is displayed when I try to open any file on a network share!

How annoying is that! Considering that I open several thousand files a day, pretty much all of which are on network shares (my servers), its just completely inconsiderate that there is no way to turn this off easily!

It also appears that I am not the only one with this problem, a google search for Open File Security Warning shows that there are many hundreds of users reporting the same problems on Windows Xp as well!

Here is the solution for Windows Vista Ultimate and Xp Professional (I havent figured out how to do it with Home editions of Xp or Vista yet)

1. Click on the Windows button/Start button

2. Click on Run

3. Type in gpedit.msc

4. Press Enter and Group Policy Object Editor will open (see attached images)

5. Click on Local Computer Policy

6. Click on User Configuration if it is not already displaying its sub-items

7. Click on Administrative Templates

8. Click on Windows Components

9. Click on Attachment Manager

10. Double-click on the Setting "Default risk level for file attachments"

11. Enable the setting and select log risk (see image attached)

12. Click on OK to close the dialog

13. Double click on the Setting "Inclusion list for low file types"

14. Enable this setting

15. Add in the file extensions you wish to be exempt from the security warning dialog. (See image attached)

16. Click on OK to close the dialow

17. Close Group Policy Object Editor

If you have Windows Vista the change is immediate, if you have Windows Xp Pro you will need to re-boot your PC.

If anyone knows how to solve this problem in the home editions where there is no Group Policy Object Editor, please let me know by posting a comment!