Hi, im researching on th KB947864 update who dont work when ie7 is install at install time (t-13 or t-12) There is a problem with the dllcache folder at install time When the installation of IE7 at t-12 begin the dllcache folder is empty. When IE7 install himself, the .dll (wininet.dll) files are well copied to the dllcache folder. But a first reboot, sometings (WPF) copy files to dllcache folder and dont look a files already present et ovewrite files from the ie7 installation with older one (ie6) So there is two problems, first the dll cache should not overwrite files without first checking for version at first boot and i dont konw why this patch look for a files into dll cache to do validate is prerequist. it shouldnt and base the installation only on present files on the windows / system32 folders. i will do a script who rename all the files from dll cache at T-12 and place information to rename them back at boot time (PendigFileRenameOperations), if the PendigFileRenameOperations take place after the WPF initiation of the dllcache, both problem will be resolve. I test and post the result here. ==== Edit 1 ==== There is the time frame of the DLLCACHE folder T-39: 20 .CAT files are copied to the folder T-13: Update specific files copied to the folder T-12: Update specific files copied to the folder T-9: (AFTER UserExecute from WinNT.SIF ) FullFiled with more than 2000 files from unknown emplacement and overite allready existing files and dont delete existing files! EUREKA I have code a script who rename files frome dllcache i test it and i let you know 2 things, if you execute the KB947864 at T-13 or T-12 it should install ok, beause of the presence of the files from from the IE7 setup done just before, there is a trick seen here: The files into the dllcache folder ARE RESETED TO IE6 VERSION and this could miss lead WU to report incorect installed patch. Stéphane