at0801, to BC Forums!
Being that you're running a Preview OS, while this is no guarantee, open "cmd" & type in the below code to check the integrity of the system files.
It's important to hit the space bar to have a blank after the sfc portion of the command. Your install media may be needed, so have it handy. And also being this is a Preview OS, some of the other options to repair this, such as the DISM tool, will likely not work.
You must keep in mind what you agreed to (I hope that you read the docs & EULA beforehand) may include a rough ride. This isn't even a Consumer Preview yet & won't be for a few more months, so for those less experienced, running in a virtual machine (as I did) is a better option.
I tried this on my main PC, and though all looked great at first, what a slap in the face after the first upgrade. Couldn't access my other OS's, until I went into the "msconfig" utility to boot to that SSD first.
This is my advice, and I highly recommend for you to accept it, though you're not required to, you're headed for a rocky road this holiday season with this computer. Oh, and did you know that there's a keylogger in this OS? Everything you type goes to MS. That's right, even the things you don't want anyone to know.
If you have recovery media for the OS that shipped with your computer (I hope that you created it, as was suggested, or a backup of your OS), I suggest that you reinstall that one. And if you wish to further test Windows Technical Preview, do it through VirtualBox. A virtual machine can do no damage to your OS or computer, unfortunately, the OS you're now running may be damaged. The recent upgrade may have made things worse & why you're receiving the errors.
That is the best advice I can offer at this time, hopefully when the Consumer Previews are released, they'll be more "road ready", with less bumps in the ride.
I have strong doubts about this being a security issue, rather a broken install, possibly from the latest upgrade. Something that your install media cannot fix, as the upgrade is newer than the media you have.
Nor has windows tech support been able to, but the people I've chatted with haven't seemed all that smart.
Not the first time I've heard that, and have had a dose of their not being able to help myself. With their last stable OS, an 8.1 upgrade.
Please let us know if we can further assist.