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Level 2

196 points

Windows 10 upgrade fail 80073B92-20009 Fusion Drive iMac

iMac 27inch Late 2013

fusion Drive

OS X 10.10.4

bootcamp partition with Windows 8.1 installed ok

the Windows 10 upgrade is ready to install however it fails every time at the reboot stage. I get error 80073B92-20009 and the upgrade fails the iMac starts up in Windows 8.1 again

The installation failed in SAFE_OS phase with an error PREPARE_ROLLBACK operation

iMac (27-inch, Late 2013), OS X Yosemite (10.10.4), Fusion Drive

Posted on Aug 7, 2015 11:51 PM

Best reply

socokid

Level 4

3,151 points

Posted on Aug 8, 2015 9:43 AM

Same exact issue, same error.

Still haven't gotten it to work...

Windows 8.1 via bootcamp, running great otherwise... but Windows 10 upgrade fails at "copying files" with that same error code.

Windows hilariously downloads the entire 2.6 GBs again on each attempt (sigh), but frustrating.

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46 replies

Dec 5, 2015 3:58 AM in response to britops

Same problem now with the latest big update of Windows 10.

Microsoft just plain *****.

Windows 10 upgrade fail 80073B92-20009 Fusion Drive iMac