To: Alexandria PC Veteran
Have you tried the newest Intel and AMD packages for your desktop? I've recently checked the available downloads for your XPS 8500 and found that there are all the needed drivers for Windows 8.1! Just grab the "Intel Integrated GFX Driver" and the "AMD AREV Driver for Windows 7, 8 & 8.1 64bit Operating Systems", and then perform an installation in a usual way (Intel's first, next an AMD's one). These are the packages I'm talking about:
You can also enter your Dell Service Tag on the "Home Support" page and choose "MS Windows 8.1 64-bit" from the "Operating System" drag-down list - this will hopefully lower the number of listed packages so you won't be able to mistake choosing the right packages for your exact model.
BTW, Dell has provided my laptop with all the needed software, so I was able to make my laptop work with Windows 8.1 just as great as with Windows 8. I hope you'll have the same experience.