I think that you might want to check your sources. According to the purchase website located here:
http://dreamfleet2000.com/Previews/181/purchase_181.html
I have extracted this quote:
"The Archer III is for FS2004 (FS9), Windows XP and Windows Vista 32* only. It will not operate in FSX. A version of the Archer III for FSX is planned for release at a later date."
What is important is in bold. I really hate when people judge you and they are wrong, for something so obvious.