Hi Gary,
Tone down your rendering settings a lot. You have a very capable machine to run XP but there is no computer yet to fully max out XP in today's time. I get 30+ fps with medium to almost high rendering options but not extreme. Tone down your rendering options to the LOWEST possible setting and increase 1 setting at a time to see how your frame rate is affected. Restart the sim to the changes take effect.
Frame Rate Rules
Below 19 is terrible
25-35 + is optimal range for XP
60 + very unlikely
My Specs
Intel i7 4770k @3.5 ghz
GTX 970 4 gb VRAM
16 gb RAM
1 TB storage
MSI Z-87 G-41 Motherboard
Hope this helps. Let me know if you need additional guidance
Go super easy on cloud puffs setting- FPS killers. I have mine at 10%
Buildings, cars, trees, HDR, and texture resolution are GPU CPU killers as well. My HDR isn't working good so I turned it off
-Rishi