Hi Dan,
First of all, we've worked very hard to get this forum to be a place of sorted information for preview releases. You should have seen what was going down, when the Insider program was first starting up and this subforum didn't exist -- I'd post a problem, and get the 3rd degree since I'm running a preview prerelease OS, and my posts would even get deleted, and I couldn't open tickets either, because it was a prerelease OS. Long story short, I convinced them that we, the community, needed a place to collect info on crashes with the Windows Insider program, so they created this forum "VirtualBox on Windows pre-releases" specifically because of people like me. So again, you really need to be posting in a non-pre-release forum.
Secondly, your issue is very clearly not the same. If you read the first post very carefully, it says "Any attempt to launch "Oracle VM VirtualBox" results in a WerFault.exe instance.", and even has the build number where the error started, build 15002+. Your issue is much different - you CAN launch the program! Then, when you try to start a VM, you get an error (yes, I see it's "0xc0000005", but that's a generic NULL EXCEPTION error code I believe), and so your problem is that process hardening is interfering with your ability to start a VM. Very different from this thread's problem.
Thirdly, you necromanced an old thread. The bug in this thread has been fixed a long time ago, if you read through the thread to see. Over a month ago, I confirmed fixes for this thread's problem, in this post:
viewtopic.php?f=38&t=81351&start=15#p382743
... and most people consider it really bad form, to reopen an old thread that had been fully solved.
Finally, to get back to your problem... Look. Oracle VirtualBox process hardening can be very difficult to work with at times. If it doesn't find signed info for everything about your OS that it needs, then it won't allow the VM to be started, because it could be injected into and is thus (to Oracle) considered insecure. To SOLVE your issue, you need to carefully work backward to figure out what the problem is -- taking notes at each step. Uninstall your Antivirus (and take a note), restart the PC, retest with both old VM and new VM. If it still doesn't work, uninstall any themes/mods (like Start menu changers, UI changers, etc) ONE AT A TIME (and take a note), restart the PC, retest. If that doesn't work, keep uninstalling stuff you'd think would interfere, until you find it. If THAT doesn't work, then you could "start fresh" with a clean install of Windows, and work FORWARD, testing after every install+restart. Hopefully, eventually, you'll find out which piece of software is interfering, then you can reinstall the rest, then you can report the problem to Oracle. If it's unsigned software, they probably will NOT whitelist it. If it's signed but interfering, they may fix it, if you report it kindly.... not in this forum :-p
Welcome, friend. I wish you luck in your adventure!
Jacob Klein