I'm responding to your personal message to me, read my first post.
What is the name of the attatchment that you are trying to open? I want the whole name (filename.example) If you answer me that I can suggest opening it with a qualified program. There are many extensions out there and some times you need software that is not included in windows to open them.
Give me that much information and I can then gladly point you in the right direction.
This may help if you read this page,
Filename extension - Wikipedia, the free encyclopedia