It was running fine last time I ran it a couple of months ago, but I was going to do a new playthrough because of The Frontier.

While getting my mods setup and ready, Windows did an update. After I finished downloading everything, got my load order setup and everything, I figured I'd reboot and let the updates install.

Right after that, I'm getting errors of a missing MSVC and MSVR file. I've reinstalled all my redistributables and directX. I tried to install Framework again too, bit I have the latest and it wasn't willing to re-install it.

I unloaded all mods, rebooted, same issue. Uninstalled FNV. Reinstalled it, it sought to repair 3 of the redistribs, I let it. Still the same issue.

I tried running as admin, and in win7 compatibility. No change. I tried with and without NVSE, I tried the launcher by itself, same issue.

I copied the .dlls it wanted into the directory, and then it just spit out a new (memory address) error and still failed.

My FO3 GOTY edition works just fine. I haven't found an issue with any other game right now (but I don't have too many installed either---still, I tested several others and they all work).

I can paste screenshots of the various error windows as needed. The only change I can think of is the Win10 update that came out yesterday.

I'm hoping someone can help out. I have my mods downloaded so it should at least be a quick install, but I'd obviously need to remodify my inis. Still, it's not even launching, either the launcher or .exe so I can't actually do any of that. I do not think it's a mod issue, as if it was the game would at least launch and I could check conflicts, this appears to be some sort of fatal system issue.

This might help.
Meanwhile you could try deleting the INI files from %USERPROFILE%\Documents\My Games\FalloutNV\ and reinstalling the required Microsoft Visual C++ 2008 Redistributable Package.

Attached is a screenshot. I tried deleting the files you suggested above and also tried reinstalling that redistrib again (repair mode), but there was no change.

This fixed it! I was able to get the launcher to run. Now I have to reinstall all the mods and probably edit a whole bunch of things. But the actual fix took mere seconds! It's too bad the repair functions don't actually work like they should. Would have saved a lot of the trouble.