Hello,

I've been trying to install Hyper-V for a while, every time failing either with error 0x800F0906 or 0x800F081F. I tried pretty much all of the available fixes that didn't involve having to reinstall the entire OS which is a total hassle I'd rather avoid unless strictly necessary.

I changed the group policy to allow the installation from Windows Update, and forced change. I rebooted in the meantime several times too. I copied the sources/sxs folder from my Windows 8.1 ISO and provided it as an extra source. I even tried to use Win10 sxs folder from the ISO. Neither of these worked.

I tried using DISM from both shell and powershell (elevated). Neither worked. Installation just gets to 66% and claims it needs sources. ScanHealth and RestoreHealth do nothing, neither does sfc /scannow.

C:\Windows\logs\CBS because I saw many threads requesting that.

• Edited by Haxton Fale Tuesday, January 20, 2015 9:19 AM

Hello Haxton Fale,

What source do you use?

I checked the log and find :
2015-01-23 11:31:07, Info                  DISM   DISM Package Manager: PID=924 TID=5236  Error in operation: source for package or file not found, ResolveSource() unsuccessful. (CBS HRESULT=0x800f081f) - CCbsConUIHandler::Error
2015-01-23 11:31:08, Error                 DISM   DISM Package Manager: PID=924 TID=3988 Failed finalizing changes. - CDISMPackageManager::Internal_Finalize(hr:0x800f081f)
2015-01-23 11:31:08, Error                 DISM   DISM Package Manager: PID=924 TID=3988 The source files could not be found; their location must be specified using the /source option to restore the feature. GetCbsErrorMsg

Please check if you mount the correct the image.
If the sxs folder in the source folder, we need to specific the path.Try to use the command dism /online /enable-feature /featurename:microsoft-hyper-v-all /All /LimitAccess /Source:Z:\sources\sxs

Best regards,
Fangzhou CHEN

I checked, then checked again, then redownloaded, checked, failed, checked that I downloaded the right one, and failed again. Unless both Dreamspark and MSDN downloads are faulty, there is nothing wrong with my Windows 8.1 ISOs.

EDIT: Just to be on the safe side, I have just redownloaded a new ISO using the Windows 8.1 installation tool. The same error occurs.

• Edited by Haxton Fale 1 hour 24 minutes ago

I checked, then checked again, then redownloaded, checked, failed, checked that I downloaded the right one, and failed again. Unless both Dreamspark and MSDN downloads are faulty, there is nothing wrong with my Windows 8.1 ISOs.

EDIT: Just to be on the safe side, I have just redownloaded a new ISO using the Windows 8.1 installation tool. The same error occurs.

• Edited by Haxton Fale Tuesday, February 03, 2015 10:21 AM

Hi Haxton Fale,

What is your environment? Do you use Windows Server Update Services (WSUS) to distribute update?

Please check the new log, if the error is still about source files, I think the ISO doesnt contain the whole hyper-v feature.
That is why you are stuck in the 66%.

If you use WSUS, please check if the setting in WSUS allow client to install the hyper-v update.

Best regards,
Fangzhou CHEN

I'm using Windows 8.1 Pro. I'm not using WSUS. I changed the group policy to allow the system to use Windows Update instead of WSUS.

The DISM log produces the exact same error - could not find sources.

As a small bonus: I have another PC with Windows 8.1 Pro. After enabling the virtualization in BIOS/CPU settings, I was able to simply download and install Hyper-V on it, without having to change anything extra, not even the group policy to allow bypassing WSUS.

• Edited by Haxton Fale 37 minutes ago

I'm using Windows 8.1 Pro. I'm not using WSUS. I changed the group policy to allow the system to use Windows Update instead of WSUS.

The DISM log produces the exact same error - could not find sources.

As a small bonus: I have another PC with Windows 8.1 Pro. After enabling the virtualization in BIOS/CPU settings, I was able to simply download and install Hyper-V on it, without having to change anything extra, not even the group policy to allow bypassing WSUS.

• Edited by Haxton Fale Friday, February 06, 2015 11:05 AM

Hello Haxton Fale

This computer is not domain-joined?

If so, I still this issue is caused by Windows update. That is why another computer can normally install the Hyper-v, it can normally update.

Can you normally use Windows update to install the update?
Please take the following steps for troubleshooting Windows update:
1. Go to Control Panel\All Control Panel Items\Troubleshooting\All Categories and run the Windows Update Troubleshooter
2. Navigate to %windir%\Windowsupdate.log , upload the Windows update log to OneDrive and share with us for analyzation.

Best regards,
Fangzhou CHEN

Here is the log. Troubleshooter found some issues and fixed it. Then I tried installing Hyper-V, that failed, then I ran the Troubleshooter again, and it found the same issues again. And it keeps finding (and fixing) the same error over and over again (Potential Windows Update Database error detected 0x80070490, and Windows Update components must be repaired).

Hello Haxton Fale

Do you use the ccommand Dism /Online /Cleanup-Image /RestoreHealth?
This command use the Windows update, it may has issues.

Please use the following steps for troubleshooting:
1. Reset the Windows Update components
http://support.microsoft.com/kb/971058/en-us
2. Run the command Dism /Online /Cleanup-Image /RestoreHealth /Source:c:\test\mount\windows /LimitAccess
to use your own source to restore the image.

For more information, please take a look at the following article.
https://technet.microsoft.com/en-us/library/hh824869.aspx

Best regards,
Fangzhou CHEN