Hi Peppino, I think I face the same problem and probably know how solve it. That “framework 3.5 sp1 family” -file contains 5 framework-files which you need download. With them you also need 3 more framework-files at least with X86. You can find the big “file” consist those 5 files at http://catalog.update.microsoft.com/v7/site/Home.aspx. Depending your os try to find correct file for you, but in might be as “Microsoft .NET Framework 3.5 Service Pack 1 and .NET Framework 3.5 Family Update (KB951847) x64”, use search key “KB951847”. It downloads folder including all those 5 files. After that I can tell how you should do with X86, but it might also work with X64. Those 3 more files are some kind of hot fixes. You can find them at Microsoft Download Center http://www.microsoft.com/downloads/en/default.aspx , use search key “Microsoft .NET Framework 3.5 Family Update for Windows XP x64, and Windows Server 2003 x64”. it leads you to download all those 3 file. With nLite I used runonce in unattended, using bat file like Addon.bat with command lines as (note: I have rename those 5 first file by cutting long ends off) ------------------------------------------ @ECHO OFF ECHO off start /wait %source%\RunOnce\Updates\X86_IA64_AMD64-all-ndp20sp2-kb958481-x86.exe /q /norestart ECHO off start /wait %source%\RunOnce\Updates\X86_IA64_AMD64-all-ndp30sp2-kb958483-x86.exe /q /norestart ECHO off start /wait %source%\RunOnce\Updates\X86_IA64_AMD64-all-dotnetfx35.exe /q /norestart ECHO off start /wait %source%\RunOnce\Updates\X86-fi-dotnetfx35langpack_x86fi.exe /q /norestart ECHO off start /wait %source%\RunOnce\Updates\X86_IA64_AMD64-all-ndp35sp1-kb958484-x86.exe /q /norestart ECHO off start /wait %source%\RunOnce\Updates\NDP20SP2-KB958481-x86.exe /q /norestart ECHO off start /wait %source%\RunOnce\Updates\NDP30SP2-KB958483-x86.exe /q /norestart ECHO off start /wait %source%\RunOnce\Updates\NDP35SP1-KB958484-x86.exe /q /norestart Exit ------------------------------ Those Runonce and Updates are just folders I add to Windows istallation CD-rom after slipstreaming everything else. After XP installation Windows Updates does not offer that Framework Family anymore. but it offer framework 3.0 language pack, at least for Finnish language. It seems to be a mistake of Microsoft, because it is not possible to install. Hope that helps you to solve the problem, even I have done that with Win XP X86 in Finnish. Maybe someone can correct these instructions for X64