It could be you Anti Vi as i don't use  sunbeltsoftware.  The ones that i know work fine with Freelancer are Avira free ( http://www.avira.com/en/avira-free-antivirus) And Avast. If it is your Anti Vi you will need to completely uninstall it (not just stop it running) as they have a tendency to leave coding behind.
Also still not much detail, what precisely happens when you try to install Freelancer......