I've used the GECK several times with no issue. I've installed windows 10 recently but I'm pretty sure I've used the GECK since then as well. I've also attempted moving the d3d0.dll out of the folder.
-Loading FalloutNV.esm, Frontier.esm, TempCompHuman.esp (my companion template)
-Cell load attempt = Goodsprings General Store
_________________“The worst thing that could possibly happen to anybody would be to not be used for anything by anybody. Thank you for using me, even though I didn't want to be used by anybody.” -Kurt Vonnegut