As it's still pooping up in Safe Mode with Networking, it's not likely to being caused by an infection.
Have you tried changing the setting as in that YT video I'd linked.
Previously I'd forgotten to suggest to see if it was possible to role that video converter program back from its updates, but as you've reinstalled it, it will now contain the updates - but it could have been coincidental that the error message was a result of those updates.
This is where system images can normally pull you out of the mire, but have you checked to see what the setting is for your restore points and if a manually created one is still there after a reboot.