We can run versions as old as 5.5 on our XP systems, so I doubt that it's a system requirements issue.
In what way does the installation fail? What error messages, if any do you see?
If I knew how I would attach a screen shot.
"You cannot install or uninstall FileMaker on this version of Windows. Please refer to the system requirements in the installation instructions for more information."
You can upload screen shots by clicking the edit link on your very first post in the thread. There's a button there for uploading a graphic. You can also upload the graphic to a file sharing site and post the download link in any post of yours in the thread...
I believe Filemaker had some hinky "activation" requirements that may be a factor here. I believe most had to resolve this with a call to customer service. That call shouldn't cost you, but I'm not a FileMaker Inc. person so don't take that as any kind of promise or guarantee to that effect...