Scott Hanselman

NOTE: I'm not involved with the Windows Team or the Windows Insider Program. This blog is my own and written as a user of Windows. I have no inside information. I will happily correct this blog post if it's incorrect. Remember, don't just do stuff to your computer because you read it on a random blog. Think first, backup always, then do stuff.

Beta testing is always risky. The Windows Insiders Program lets you run regular early builds of Windows 10. There's multiple "rings" like Slow and Fast - depending on your risk tolerance, and bandwidth. I run Fast and maybe twice a year there's something bad-ish that happens like a bad video driver or a app that doesn't work, but it's usually fixed within a week. It's the price I pay for happily testing new stuff. There's the Slow ring which is more stable and updates like once a month vs once a week. That ring is more "baked."

This last week, as I understand it, a nasty bug made it out to Fast for some number of people (not everyone but enough that it sucked) myself included.

I don't reboot my Surface Book much, maybe twice a month, but I did yesterday while preparing for the DevIntersection conference and suddenly my main machine was stuck in a "Repairing Windows" reboot loop. It wouldn't start, wouldn't repair. I was FREAKING out. Other people I've seen report a Green Screen of Death (GSOD/BSOD) loop with an error in volsnap.sys.

TO FIX IT

The goal is to get rid of the bad volsnap from Windows 10 Insiders build version 17017 and replace that one file with a non-broken version from a previous build. That's your goal. There's a few ways to do this, so you need to put some thought into how you want to do it.

NOTE: At the time of this writing, Fast Build 17025 is rolling out and fixes this, so if you can take that build you're cool, and no worries. Do it.

1. Can you boot Windows 10 off something else? USB/DVD?

Can you boot off something else like another version Windows 10 USB key or a DVD? Boot off your recovery media as if you're re-installing Windows 10 BUT DO NOT CLICK INSTALL.

• You may need to do special keystrokes to boot off your USB key. On Lenovo it's F2, or F10. On Surfaces it's Power+Volume Down. Go search for "boot off usb MANUFACTURER NAME" for your computer!
• Do you not have a copy of Windows 10 you can put on an 8 gig or larger USB? You can use this download tool on another machine to make a bootable Windows 10 USB.

When you've run Windows 10 Setup, instead click Repair, then Troubleshoot, then Command Prompt. It's especially important to get to the Command Prompt this way rather than pressing Shift-10 as you enter setup, because this path will allow you to unlock your possibly BitLockered C: drive.

NOTE: If your boot drive is bitlockered you'll need to go to https://onedrive.live.com/RecoveryKey on another machine or your phone and find your computer's Recovery Key. You'll enter this as you press Troubleshoot and it will allow you to access your now-unencrypted drive from the command prompt.

At this point all your drive letters may be weird. Take a moment and look around. Your USB key may be X: or Z:. Your C: drive may be D: or E:.

2. Do you have an earlier version of volsnap.sys? Find it.

If you've been taking Windows Insiders Builds/Flights, you may have a C:\Windows.old folder. Remembering to be conscious of your drive letters, you want to rename the bad volsnap and copy in the old one from elsewhere. In this example, I get it from C:\Windows.old.

ren C:\windows\system32\drivers\volsnap.sys C:\windows\system32\drivers\volsnap.sys.bak
copy C:\windows.old\windows\system32\drivers\volsnap.sys  C:\windows\system32\drivers\volsnap.sys

Unfortunately, *I* didn't have a C:\windows.old folder as I used Disk Cleanup to get more space. I found a good volsnap.sys from another machine in my house and copied it to the root of the USB key I booted off up. In that case my copy command was different as I copied from my USB key to c:\windows\system32\drivers, but the GOAL was the same - get a good volsnap.sys.

Once I resolved my boot issue, I went to Windows Update and am now updating to 17025.

PLEASE, friends - BACK UP YOUR STUFF. Remember the Backup Rule of Three.

Here's the rule of three. It's a long time computer-person rule of thumb that you can apply to your life now. It's also called the Backup 3-2-1 rule.

• 3 copies of anything you care about - Two isn't enough if it's important.
• 2 different formats - Example: Dropbox+DVDs or Hard Drive+Memory Stick or CD+Crash Plan, or more
• 1 off-site backup - If the house burns down, how will you get your memories back?

Beta testing will cost you some time, and system crashes happen. But are they a nightmare data loss scenario or are they an irritant. For me this was a scary "can't boot" scenario, but I had another machine and my stuff was backed up.

Don't take beta builds of anything on your primary machine that you care about and that makes you money.

DISCLAIMER: I love you but this blog post has NO warranty. I have no idea what I'm doing and if this makes your non-bootable beta software machine even worse, that's on you, Dear Reader.

Sponsor: Check out JetBrains Rider: a new cross-platform .NET IDE. Edit, refactor, test and debug ASP.NET, .NET Framework, .NET Core, Xamarin or Unity applications. Learn more and download a 30-day trial!

About Scott

Scott Hanselman is a former professor, former Chief Architect in finance, now speaker, consultant, father, diabetic, and Microsoft employee. He is a failed stand-up comic, a cornrower, and a book author.

About   Newsletter

Hosting By