After a three-week delay, Microsoft’s Outlook E-mail Security Update is now available for free download for Outlook 98 customers at

The upgrade aims to protect users of the popular email program from spreading viruses or worms by blocking access to files which may be deemed too unsafe to open.

Once the patch is installed, users will be prompted with a warning dialog box if and when an outside program attempts to access their Outlook address book or deliver e-mail without intervention, according to a Microsoft representative.

Microsoft found itself in the line of fire last month and was left to answer mounting criticism that Outlook too easily helped propagate and spread the "I Love You" worm worldwide.

The software giant decided to postpone and tweak its original update release because users and security experts expressed concerns over the lack of functionality provided by the initial patch.

Microsoft went back to the drawing board and implemented new customisation features that allow administrators to choose which types of files can be accessed and how warning boxes are displayed that best fits their deployed server security levels.

According to Microsoft, the entire Microsoft Office program must be removed if a user installs the new patch and then decides to remove it.

This all-or-nothing approach irked users during news of the first patch release.