I've gone back to fill in the gap of my TES experience, and installed Morrowind on my laptop under windows 10. Got MGE XE and Mash to work there without any problems, and played for a time.

Then I decided to move it all to my desktop/gaming machine which runs Windows 7 Pro. The game and MGE work, but I can't get Wrye Mash to start up. Running Python.exe from the command prompt gets me "wx.py can't be loaded" on the laptop where it works! Even with that resolved on the desktop, I still get nowhere. Now it's import _core_ filing with "ImportError: DLL load failed: $1 is not a valid Win32 application." I'm suspecting some kind of 32/64 bit conflict, but can't see which direction to go next.

Meanwhile, I can still play, just without Mash's help.(except under Win 10, sitting in a less comfortable chair!)

I checked the versions, and indeed I had the 64-bit wxPython with the 32-bit Python 2.6.6. However, fixing that just gets me to another "cannot be loaded" situation. The copy that runs in Win 10 is 2.6.5. I'm reluctant to fall back a level under win 7, as that has a working NifSkope etc on top of it.

Wrye Bash for Skyrim and Oblivion is the standalone 3.0.5/6, so not involved. I have one release for Oblivion, and added the other for Skyrim.

I suspect you tried to launch the old Wrye Mash 84. Correct?

Try Melchor's http://download.fliggerty.com/download-58-141 (WMSA) since it's bug free and can be installed outside of the Morrowind\Mopy folder, which is required for a Python version.

That means you can actually use two different Wrye Mash at the same time, very useful for mod testing purposes.

Also, http://www.gamesas.com/topic/1601492-wrye-mash-thread-7/ the OP about the difference between the different versions of Wrye Mash.

I actually tried the standalone WMSA one first, and that failed. My hope was the non-wrappered version would be more helpful when it errored.

Well, I deleted all traces of Mash, and started again. Windows hung trying to run the security check on the downloaded WMSA, so I didn't trust that copy and went and got the one from the Win 10 installation on my laptop, via thumb-drive. That seems to have worked. I suspect a Win 7 bug related to the earlier download, giving me a corrupt copy of WMSA the first time. Treat the Python instance as a failed experiment in between.

The latest copy runs.