I'm trying to get Dedup working on Windows 8.1 Update 1. I tried using the CMD script and DISM, but two of the necessary packages wouldn't install. I tried the powershell scripted version of dism instead (blog.compower. org/2014/02/20/enable-deduplication-windows-8-1) and got a similar result, one CAB still wouldn't install. The error was meaningful, but I don't know what to do next. Things I've checked: Package files taken fresh from a "known good" Server 2012 R2 with the 2014 Spring Update installed and Deduplication enabled and working correctly. Destination system is Windows 8.1 x64 with the 2014 Spring Update. Winver for both is identical (6.3 build 9600) The standard commands to find and fix servicing issues are all error free (sfc/scannow, dism /scanhealth, chkdsk) The error reports from PowerShell and DISM say what's going on but not how to fix it: > Add-WindowsPackage -Online -PackagePath "C:\DeDupCabs\Microsoft-Windows-Dedup-Package~31bf3856ad 364e35~amd64~~6.3.9600.16384" -NoRestart VERBOSE: Dism PowerShell Cmdlets Version 126.96.36.199 VERBOSE: Target Image Version 6.3.9600.17246 WARNING: Failed to add package C:\DeDupCabs\Microsoft-Windows-Dedup-Package~31bf3856ad364e35~amd64~~6.3.9600.16384 WARNING: Add-WindowsPackage failed. Error code = 0x800736cc Add-WindowsPackage : A component's file does not match the verification information present in the component manifest What's needed to workaround this?