Windows Update broke game launcher

Hello, and thank you for any support given :)

Long version: Windows bugged me for an update and I finally consented last night. I shut down and updated, and come today when I tried to launch FFXIV I receive an error message saying that it couldn't find WMVCore.dll [I was able to log in, but only got the message upon hitting PLAY]

Just to double check, it seemed to only affect FFXIV. All the other games/programs I tried seemed to be working perfectly fine.

After a quick google-ing I find someone who recommends just copying the file from windows.old/system32 to windows/system32. It was indeed in the old folder but not the new, so I copied, and that message went away. The next attempt at launch I get two new messages with 2 different dll's [can't remember the names, unfortunately]

I repeat the process, similar presence/absence in old and new respectively. Upon next attempt I instead receive a ffxiv_dx11.exe application error [unable to start correctly (0xc0000142)].

Thinking DirectX11 is the problem, I turn off support [reverting to 9.0c it seems] which then bumped me back to not being able to find WMVCore.dll. I double checked and it was still in both windows.old/system32 and windows/system32, as were the other two [I could remember their names at the time]. I turn DirectX11 back and on it's still giving the unable to start error.

At this point I go into Config, use the backup tool to store my precious hotbars and macros [I think they're local?] and then hit Reset System Settings. I confirm and nothing really shows as happening...I assume that's normal.

No change in errors, so I decide to fully uninstall and reinstall [just using add/remove through windows, if that makes a difference]. Downloaded a new installer, shut off firewall [just the standard windows one], installed with Heavensward as prompted.

Cut to one 30GB download/installation later, boot back up, and the exact same errors are still there for both DX11 and DX9 [Unable to start and can't find WMVCore.dll, respectively]

A bit more google-ing and a different recommendation for downloading the Windows Media Feature Pack is found. Ran it, no change. I then see if I can update DirectX myself. The installer tells me my version is more current, and the installer itself does nothing. Needless to say [but I will, why not?] no change there.

As a last resort, I went and updated my video drivers through GeForce Experience. No luck there either.

There were usually computer restarts at most points between steps, just to try to be thorough. At this point my knowledge and search-fu have been tapped out, and thus...here I am :D. I'll provide some technical copy-pastes in case they convey anything I probably missed. I appreciate any help/insight on this matter, and am curious how it'll all turn out.

TL;DR: Updated windows last night and it broke the game launcher. Copy-pasted some DLL files, reinstalled, directx shenanigans, couldn't fix it. Cursed by Live Letter Hype D:

Operating System Info [Unfortunately, I don't know/remember previous version :(

Edition: Windows 10 Home N
Version: 1703
OS Build: 15063.296
System Operating Type: 64-bit operating system, x64-based processor

Some info from DXDiag...what I assume could be relevant. Otherwise it'd be way too much.

Card name: NVIDIA GeForce GTX 970
Manufacturer: NVIDIA
Chip type: GeForce GTX 970
DAC type: Integrated RAMDAC
Device Type: Full Device
Device Key: Enum\PCI\VEN_10DE&DEV_13C2&SUBSYS_36841458&REV_A1
Device Status: 0180200A [DN_DRIVER_LOADED|DN_STARTED|DN_DISABLEABLE|DN_NT_ENUMERATOR|DN_NT_DRIVER]
Device Problem Code: No Problem
Driver Problem Code: Unknown
Display Memory: 12225 MB
Dedicated Memory: 4059 MB
Shared Memory: 8166 MB
Current Mode: 1920 x 1080 (32 bit) (60Hz)
Monitor Name: Generic PnP Monitor
Monitor Model: VE247
Monitor Id: ACI2493
Native Mode: 1920 x 1080(p) (60.000Hz)
Output Type: DVI
Driver Name: C:\WINDOWS\System32\DriverStore\FileRepository\nv_dispi.inf_amd64_7209bde3180ef5f7\nvldumdx.dll,C:\WINDOWS\System32\DriverStore\FileRepository\nv_dispi.inf_amd64_7209bde3180ef5f7\nvldumdx.dll,C:\WINDOWS\System32\DriverStore\FileRepository\nv_dispi.inf_amd64_7209bde3180ef5f7\nvldumdx.dll,C:\WINDOWS\System32\DriverStore\FileRepository\nv_dispi.inf_amd64_7209bde3180ef5f7\nvldumdx.dll
Driver File Version: 22.21.0013.8233 (English)
Driver Version: 22.21.13.8233
DDI Version: 12
Feature Levels: 12_1,12_0,11_1,11_0,10_1,10_0,9_3,9_2,9_1
Driver Model: WDDM 2.2
Graphics Preemption: DMA
Compute Preemption: DMA
Miracast: Not Supported
Hybrid Graphics GPU: Not Supported
Power P-states: Not Supported
Driver Attributes: Final Retail
Driver Date/Size: 5/16/2017 5:00:00 PM, 885216 bytes
WHQL Logo'd: Yes
WHQL Date Stamp: Unknown
Device Identifier: {D7B71E3E-5082-11CF-C157-89161BC2DB35}
Vendor ID: 0x10DE
Device ID: 0x13C2
SubSys ID: 0x36841458
Revision ID: 0x00A1
Driver Strong Name: oem53.inf:0f066de3ad0bda5c:Section088:22.21.13.8233:pci\ven_10de&dev_13c2
Rank Of Driver: 00D12001
Video Accel:
DXVA2 Modes: DXVA2_ModeMPEG2_VLD DXVA2_ModeVC1_D2010 DXVA2_ModeVC1_VLD DXVA2_ModeH264_VLD_Stereo_Progressive_NoFGT DXVA2_ModeH264_VLD_Stereo_NoFGT DXVA2_ModeH264_VLD_NoFGT DXVA2_ModeHEVC_VLD_Main DXVA2_ModeMPEG4pt2_VLD_Simple DXVA2_ModeMPEG4pt2_VLD_AdvSimple_NoGMC
D3D9 Overlay: Supported
DXVA-HD: Supported
DDraw Status: Enabled
D3D Status: Enabled
AGP Status: Enabled
MPO Caps: Not Supported
MPO Stretch: Not Supported
MPO Media Hints: Not Supported
MPO Formats: Not Supported