Origin is not running error [SOLVED]

I've been trying to get the game working on my kid's Windows 10 computer for several days and I'm about at my wits end. It works fine on my own Windows 7 PC - in fact, mine is a hodgepodge of Skidrow, Fitgirl and the Parenthood update from here, so I guess the fact that it actually worked lulled me into a false sense of security. Anyway, the first time I tried installing it on hers, it didn't work, so I figured maybe it was because things were from all over the place, so I uninstalled it all and downloaded the complete set from here and installed it according to the instructions. Except it still doesn't work. I have tried:
Uninstalling AV software. She originally had Avast, so I got rid of it. Then I discovered McAfee was bundled on her PC too, so I got rid of that too. That left Windows Defender, which didn't look to be so easy to get rid of, so I added exceptions to the Bin folder and the .dll's themselves and turned off the real-time protection.
I also added the game to Windows firewall.
I moved it to Program Files (she has a 64 bit PC).
I renamed the folder to The Sims4 instead of The Sims 4.
I installed CCleaner to scan for registry errors and cleaned it all up in case some lingering nonsense was interfering.
I tried running as administrator.
And finally, like a fool, I actually tried installing Origin because I saw a couple of people here say that worked for them. Alas, it did not work for me so I went right ahead and uninstalled it again.
Anyway, it's after midnight so I'm giving up for the night, but if anyone has any suggestions for what to try next, I'll try 'em all in the morning. Thanks.

I had this same problem, tried a million things similar to you and when I finally was feeling defeated tried one last thing I had seen mentioned and it worked. I just moved the whole Electronic Arts folder to an entirely different drive (where I wanted it to be anyway) and then the game loaded perfectly. Hope this helps, good luck.

Hmm. She doesn't have another drive on that PC, but I can try running it from my external hard drive and see if that makes a difference.

The .dll files are there, but I'll try redownloading them. I have to wait until she's done using the computer for the day though.

I'm afraid neither of those suggestions worked.

Yep, I read that topic and pretty much the only things I didn't do was try the Ultimate Fix because it's outdated, or the thing with the iPhone because we're an Android household. There was no Origin cache folder, although I suppose there might be one now, and I also didn't try fiddling with a VPN, I guess that's something I could try. But first, I'll give all that lot a try, thanks.

OH MY GOD. I was in the 'add/remove Programs' bit, just about to uninstall the game again, and I spotted the problem. Effing Web Companion. I didn't spot it before because I was looking under L for Lavasoft Web Companion! I feel so stupid. But why the heck did anyone think this PC needed to come pre-bundled with three AV programs? Anyway, of course, once it was uninstalled, it started working. Thank you for trying to help me!