Error code 0xc0000005

I work in a shop where the desktops run windows XP SP2. I have a user who is trying to open attachments sent through outlook version 2003 the document opens but is followed by the error code listed in the title. I ran ms updates & installed ms java, but was unscuccessful. I can save the attachement and open it without error. I recently installed an application known as Workshare onto her desktop, but I am not convinced this is causing the problem because other users have never reported any to date. Any advice or fixes that can be offered would be greatly appreciated.

Thx