Question- Unknown publisher

Hi that is the first question I post on Major Geeks, been here already for a while as an active user in the software section and loving every moment in here:cool

I am new in the development world, devloped a tool for my own use and would like to send it to my friends. The problem is that Microsoft mark me as Unknown publisher and with win 7, it almost seems as a virus with their scary messages.

Is there a free way to solve the problem? and if not, what should I do to get rid of that message?

I hope my question is published in the right forum and if not, my aplogize!

Thank you in advance for all the helpers