Hello, I tried to test an integration of Win8.1 x64 updates with Wintoolkit 1.5.3.3 using latest ISO of WIN 8.1 pro (38 updates and the 9 of .NET FW 3.5 of my UL). I encountered an error message with KB2976536 and KB3010788 : "invalid architecture". I've put them in "SFX Silent install section" ans will report the results. Log : Title: 2 update(s) skipped. ErrType: Error Description: More information is available by clicking the '>> Details' button. Exception: Invalid architecture: '...\Windows8.1-KB2976536-x64.msu' Invalid architecture: '...\Windows8.1-KB3010788-x64.msu' SOLVED : there were some x86 KBs in a x64 integration. EDIT : RunOnce installer doesn't appear during Windows 8.1 installation, I don't know if it works. EDIT 2 : Some KBs correctly integrated with Win Toolkit are asked after installation by WU. KB2992611, KB29993958, KB3006226, KB2975719, KB2976536, KB2984006, et KB2995388, and KB3003667. Used ISO is the last one from MS (october 14). Is there a particular sequence to integrate KBs as it was the case for the previous ISO ? EDIT 3 : I use the latest DISM version that was asked by a previous version of Win toolkit.