*UPDATE FIXED*  Yesterday Microsoft released KB4476976 which after applying and rebooting resolves the Sysprep issue seen after cleaning up the previous version of Windows.     Tyler
See Workaround at bottom of post. Deleting the previous version of Windows prior to running Sysprep on a reference build will result in the following. c:\windows\system32\sysprep\panther\setuperr.log 2018-10-03 14:34:04, Error SYSPRP RemoveUninstall:Failed to instantiate uninstall interface; hr = 0x80070003[gle=0x00000003]2018-10-03 14:34:04, Error SYSPRP Sysprep_Clean_Opk:Failed to remove Uninstall; hr = 0x80070003[gle=0x00000003]2018-10-03 14:34:04, Error SYSPRP ActionPlatform::LaunchModule: Failure occurred while executing 'Sysprep_Clean_Opk' from C:\Windows\System32\spopk.dll; dwRet = 0x3[gle=0x00000003]2018-10-03 14:34:04, Error SYSPRP SysprepSession::ExecuteAction: Failed during sysprepModule operation; dwRet = 0x3[gle=0x00000003]2018-10-03 14:34:04, Error SYSPRP SysprepSession::ExecuteInternal: Error in executing action for Microsoft-Windows-Sysprep-SpOpk; dwRet = 0x3[gle=0x00000003]2018-10-03 14:34:04, Error SYSPRP SysprepSession::Execute: Error in executing actions from C:\Windows\System32\Sysprep\ActionFiles\Cleanup.xml; dwRet = 0x32018-10-03 14:34:04, Error SYSPRP RunPlatformActions:Failed while executing Sysprep session actions; dwRet = 0x32018-10-03 14:34:04, Error [0x0f0070] SYSPRP RunExternalDlls:An error occurred while running registry sysprep DLLs, halting sysprep execution. dwRet = 0x32018-10-03 14:34:04, Error [0x0f00a8] SYSPRP WinMain:Hit failure while processing sysprep cleanup providers; hr = 0x80070003 Workaround: Do not delete the previous version of Windows prior to running ImageAssist. During the ImageAssist process, do not select the Auto-capture feature. The ImageAssist process will Sysprep and shutdown the machine. You will capture the image manually using the ImageAssist USB drive. Prior to booting to the USB drive, modify the following file: Dell_Tools\start.cmd & update the executable command to launch line as follows: ::Command to Launchcall x:\windows\system32\Capture_Tool.exe /winoldskip This will automatically launch the capture tool & add the Windows.Old directory to the DISM exclusion list during the WIM capture process.   Set the USB back to it's original command launch state: ::Command to Launchcall x:\windows\system32\Selector_Tool.exe
W10 1809 Sysprep fails deleting previous version of Windows