Video Settings? 13" Retina, Yosemite, PD10, Win 8.1

I am running a Macbook Pro Retina 13" with Yosemite, PD 10, and Windows 8.1. I am running the laptop with "best for Retina" 1280x800 and I wish to do the same for Windows. What are the exact settings using the 13" Retina, Yosemite, and PD 10 in order to achieve this? The documents that I was able to look up including ones that say they reference PD 10 do not show the exact settings to achieve this result.

Earlier using PD 9 and Mavericks with Windows 8.1 on the same retina laptop I was somehow able to achieve the correct effect and when I did the PD 10 and Yosemite upgrades Windows 8.1 retained the correct settings, but I was recently forced to reinstall the system and I am unable to find the correct settings using Yosemite and PD10.

TIA, David

 

UPDATE: All of the knowledge base documentation and the current manual appears to be out of date. For example, the Parallels 10 for Mac Users Guide, P. 166 which is the page for changing the video settings, shows Windows 7 instead of the current Windows 8.1. Please fix the documentation to reflect today's software (Yosemite, PD10, Windows 8.1). Thank you.