Hi Bob,
I am not from Laminar Research either; just another flight simmer.
Greengolfer15 has given you a link to download the latest version of XPUIPC. The link as shown will give you an error that it does not exist.
The site intended does exist but follow the advice given now given
1. Double click on the link provided. It should drop into your search bar of either google or your search engine. Don't click anything yet
2. At the end of the link showing in the the search bar there is a small comma. Move your mouse to immediately after the comma.
3. Backspace your mouse cursor so that the comma disappears.
4. When done press enter on your keyboard and the intended site will open.
5 Double click on the latest file version and it will download to your "downloads" folder.
6. Follow the instructions as given by Greengolfer15.
Good luck
Glenn