Using Disk Management(Admin account) create a new volume in unallocated space. If all drive has been allocated you might use Disk Management "shrink" to unallocated enough space(5G~20G depending on how much you expect to use). I used 20G since I have over 800G unallocated. I assigned the drive letter of "Z", far away from my existing drive letter uses.

Copy the C:/Sierra Fold and Paste into "Z:/". Remove all the DATA folder changes of the Widescreen patch; in my case a copy of the DATA folder pasted over(replacing) Z:/Sierra/EmperorRotMK/DATA.

Deleted Z:/Sierra/EmperorRotMK/Emperor.exe the editor doesn't need the game EXE; but you could simple replace it with the original EXE file replaced by the Widescreen patch, in case you should have a hankering for the 4:3 ratio nostalgia .

Change PIFs(shortcut tab) of EmperorEdit from C:/... to Z:/Sierra/EmperorRotMK; two lines 'Target' and 'Start in'. Note: You cant use the Widescreen patch Ingame 'Campaign Creator' button as it will error out when preforming a security check to open EmperorEdit.exe.

Use the shortcut to verify that the china maps have been normalized, so you are assured that your Emperor Campaigns Empire Map placements are not wonky looking for players.

When I next reset my OS, I may do the entire Widescreen patch thing on Z:/ after a normal Emperor install on C:/. I would also keep the modding stuff on the Z:/ drive so the original game install isn't altered in any way. Cool, and ethically more sound, yes.
Oh-oh, how about a new drive letter for each Mod so there be no conflicts. Brain-storming or brain-fart?
Must hire a programmer to alter notepad++ & hack sgreader for modding toolkit!
Yeehaa, come on buttercup, we gonna pull this place into the 21 century!

PS: I flubbed the logical drive thing, creating a primary partition instead. NP, I need to clean out the dust from the PC anyway and remove an unused aging hard drive. When its back together, I will use the new MS Fresh Start reset. That creators update thing looks interesting.
Hope to be back in a few days.

update: 10-17-2017
D:/(97G) is for old games original installation. EmperorEdit shortcut launches from this location. no file deletions. (playintromovie=no) & multiplayer fixes.
E: CD drive
F:/(9.76G/9.09G free space) Widescreen patch mod. Deleted the Editor EXE+related files, PDFs(shortcuts to D:/), deleting Audio Folder content as I turn off all sound. Binks folder emptied and binkw32.dll removed (playintromovie=no) & multiplayer fixes.
G:/(9.76G/8.95G free space) Widescreen + Japan Mod. I emptied the contents from Audio, RES, Cities(Open Play launches but no map files means it useless), Campaigns(except for Xia tutorial pak, which is needed to placate the system and Chronicles of Wei.pak), several needless files removed for launching a multiplayer campaign and campaign creation. Binks folder emptied and binkw32.dll removed(playintromovie=no). deleted PDFs(shortcuts to D:/).

Note: I have the Home edition of Win10 this setup works best for me. I tried messing with 'Start in: D:/...' but it resulted in corrupted data integrity. I have added H:/ drive in case WSGF answers my request for a modded EmperorEdit for 1600x900 resolution.
Note: with Win10 creators update(Dec 2017) the binkw32 is required.(shrug)

Onward to install Poseidon---!
Zeus & Poseidon installed on D:/, removed unneeded Pifs.

next thing todo is the Installshield renaming for Emperor install in preparation for Cleo installation...tomorrow.

update:
Cleo and Posd installed.
Posd widescreen patch applied(I:/ logical drive); all is setup to my liking. Audio folder contents removed, bik files deleted, empty file Zeus_Intro_HiQ.bik created.
I don't know if I will be installing C3 or when I will complete Cleo WS patch. Not much interest with playing those two, presently.

[This message has been edited by user3 (edited 01-02-2018 @ 11:10 AM).]