ambo: thanks for your answer, but sorry, i coulnt work Windows Sidebar on 2003x64 for a brief explanation of my OS: 2003x64 R2 Enterprise on ntfs drive c:\, SP2, .net2.0, .net3.0, IE7, wmp10 (no wmp11 for 2003x64, but i dont think the problem comes from here).. and all updates are done (20080531 22:34, 0 updates needed, included optionals ) alky instaleld to "C:\Program Files (x86)\Alky for Applications" but right click and install of Sidebar.inf had always turn back with: "INF Install failure. Reason: Could not retrieve the system message. You may run out of the system resource." and as expected after this warning: no folder of side bar neither at "C:\Program Files (x86)\" nor "C:\Program Files\" no add/remove program componenet. here what i tried: i had already tskill.exe in my system32 folder (from Windows installation). I changed it with the one rick gave (verified sure), but no improvement. i copy "C:\Program Files (x86)\Alky for Applications" to "C:\Program Files\Alky for Applications", no improvement. i tried both Ricks_WindowsSidebar_Alky2k31.1_AddOn.7z and Ricks_WindowsSidebar_AlkyXP1.1_AddOn.7z after tskill solution for xp64, i think only 2003x64 left without vistasidebar