so after quite a bit of tinkering here is how you get it to work in windows 10
install the xbox app from windows store
if you havent redeemed the code, do it from this app or the windows store website
open windows powershell in administrator (search power shell then right click and click run as administrator.)
copy/paste this (this will reinstall any thing windows needs by default for the store and xbox app)
Get-AppXPackage | Foreach {Add-AppxPackage -DisableDevelopmentMode -Register "$($_.InstallLocation)\AppXManifest.xml"}
push enter
restart your computer
open xbox app
search for the halo you bought and when you click it, it should now take you to the store and install should be available.