After all the searching and asking here, nobody seems to be able to provide information about which updates I can integrate into Windows 8.1 Pro VLK .ISO that already has Update 1 built-in? Here is the list of Baseline updates from WHDownloader - . I know that not ALL of them are present in official Update 1 .ISO. Could someone please let me know which Baseline updates I should integrate into .ISO that already contains Update 1? Is 1.08 the latest Toolkit version? I also found Win Toolkit 188.8.131.52. Which one is the best for update/hotfix integration?