Microsoft improved the latest Windows 10 pre-release build of 2014 in two important ways today. It made the build available via downloadable ISOs, letting testers clean install this build directly to a PC or VM, without having to first install the previous preview builds over each other. And it issued a fix for build 9879 that it says addresses a major BSOD error.
First, the ISOs.
You can find the ISOs on the Windows web site. As with the initial Windows Technical Preview build, you will find 32-bit and 64-bit versions of the ISOs available in a variety of languages. The US English versions are 3 and 3.9 GB, respectively.
I previously wrote about the problems trying to clean install this build in Windows Technical Preview Install Guide: Clean Install. Long story short, before Microsoft issued the ISOs today—the first time it's done so for any build but the original one—you had to install the original Windows Technical Preview build and then install the next two milestone builds, and whatever other updates were available. It wasn't a real clean install, in other words.
But build 9879 has many other problems. It is much less reliable than the previous Windows Technical Preview builds, as I've noted across a few articles—Here's a Fix for Some OneDrive Problems in Windows Technical Preview Build 9879 and Windows Technical Preview Build 9879: The Morning After, for example—and it's not clear yet whether today's fix actually addresses any of the problems I've been seeing.
Regardless, the advice hasn't changed: After you install any pre-release Windows 10 build, make sure you clear out Windows Update, installing any updates that appear for the technical preview in particular. Today's update is listed as KB3019269, but as you can see there is absolutely zero information there for now. According to Microsoft's Gabe Aul, this fix is for the "0xAB bluescreen that some were hitting."
The issue I'm seeing—which makes File Explorer unresponsive—is apparently a common GDI leak that impacts many users as well. Hopefully we'll see a fix for that as well. But you can "fix" it manually by killing the Windows Explorer process in Task Manager.