Answers
My relative uses a PC with Windows. Is there any Windows software comparable to Reunion?
We don't believe there is any genealogy software for Windows that compares to Reunion 9 for the Macintosh. Since we only create and use software for the Macintosh, we can't make a recommendation about (and aren't that familiar with) Windows software.
If you can't convince your relative to buy a Mac, our best advice would be to visit the following web page...
http://www.cyndislist.com/software.htm
It contains a number of links to different genealogy programs.