Error -2146697203

[PaleBlueMoon]

How's that for an error number?

Context:
I recently had to perform a system restore on my computer. I've never encountered this error before, and am playing XIV on PC (running Windows 7). After trying to start the launcher, I get the "checking updater/launcher version" message, followed immediately by the launcher screen, completely white (news and login bars not loading, etc.), with the aforementioned error message displayed.
A screencap:


I've tried:

• Uninstalling and reinstalling FFXIV
• Deleting the "My Games\My Documents\FINAL FANTASY XIV - A Realm Reborn" folder.
• Restarting the computer.
• Based on having been told that the launcher runs through IE: in Internet Explorer's Internet Options, in LAN Settings checking "Automatically detect settings", and in Advanced -> Settings checking "Allow software to run or install even if the signature is invalid."

None of which have worked, or produced any apparent change in the launcher's behavior.