On boot as I was getting a GSOD about 3 seconds after getting to the login page of Windows 10 17074 Insider Slow.
GSOD said it was atc.sys that was causing the crash.
Uninstalled Bitdefender 2018 - by getting to the Command prompt and renaming the folders then fully uninstalling once booted.
No more issues - so far.
I had the same issue and there was a chat with Bitdefender Support agent.
He refused to help after saying mine was a insider build.
Your workaround seems the only fruitful one right now :)
Just wanted to verify, I'm having the same problem here.
Strangely, it's only on my newer Alienware laptop, and not on any of my other older computers.
<BTW> Another fix is to boot to Safe Mode, then just uninstall.