dism mount of install.wim gets bad format error (header mismatch)

I am attempting to use dism to mount install.wim for build 10240 (the current publicly available build), and dism gets an error 11, which is incorrect format error. dism lists the image correctly, and it is the only image in the .wim

Command:
C:\WINDOWS\system32>dism /mount-image /imagefile:c:\files\windows\install.wim /index:1 /mountdir:c:\mount


The log file has the following entries:

2015-10-19 10:56:30, Warning DISM DISM WIM Provider: PID=5716 [ReadWimHeader 1723) -> version/header mismatch] c:\files\windows\install.wim (HRESULT=0x8007000B) - CWimManager::WimProviderMsgLogCallback[5716] [0xc144012e]
2015-10-19 10:56:30, Error DISM DISM WIM Provider: PID=5716 [WIMCreateFile 425) -> Fail to read WIM header] c:\files\windows\install.wim (HRESULT=0x8007000B) - CWimManager::WimProviderMsgLogCallback
2015-10-19 10:56:30, Error DISM DISM WIM Provider: PID=5716 TID=7024 WIM open failed. - CWimImageInfo::Mount(hr:0x8007000b)
2015-10-19 10:56:30, Error DISM DISM Imaging Provider: PID=5716 TID=7024 base\ntsetup\opktools\dism\providers\imagingprovider\dll\genericimagingmanager.cpp:817 - CGenericImagingManager::InternalOpMount(hr:0x8007000b)
2015-10-19 10:56:30, Error DISM DISM Imaging Provider: PID=5716 TID=7024 base\ntsetup\opktools\dism\providers\imagingprovider\dll\genericimagingmanager.cpp:737 - CGenericImagingManager::InternalCmdMount(hr:0x8007000b)
2015-10-19 10:56:30, Error DISM DISM Imaging Provider: PID=5716 TID=7024 base\ntsetup\opktools\dism\providers\imagingprovider\dll\genericimagingmanager.cpp:535 - CGenericImagingManager::ExecuteCmdLine(hr:0x8007000b)
2015-10-19 10:56:30, Info DISM DISM.EXE: Image session has been closed. Reboot required=no.

Anyone else encounter this error?

The .wim from the media upgrade tool is compressed and doesn't work. Are you trying to use that?

Download the ISO from Tech Bench - it works just fine.

I'm downloading it now. Thanks for the TechBench ref. I'm also signed up for the Insider program, I should have guessed that the public wim image would be unusable for anything but actually upgrade/install and tried an Insider ISO. I'm doing some research work on the image, not something particularly useful.

Thanks again
Jon

The Retail ISO contains a MediaMeta.xml file that locks the install.wim
thus preventing Dism from using it

Good to know, thanks. I just downloaded a techbench ISO, I assume from the post by halasz that I won't have trouble with it. As I mentioned, this is not for anything terribly important.

The techbench ref is important to me, however. I'll be doing freelancing, and I'll probably be helping my customers with upgrading to Windows 10.

Thanks again to all who have commented
Jon

Just wanted to let everyone know, I just successfully mounted install.wim with Windows 7 dism. (Slow as molasses on my severely under-powered Dell Dimension 4500). Thanks so much for the tips.

So the answer is: use a copy of the ISO that is designed for install.wim to be mounted...:)

Jon