Hello In fact I "accidentaly" got hold on a fixed and official Kernel32.dll from Microsoft, which exports the GetLogicalProcessorInformation function you need. The method used by WantSkaipBack, as show in the youtube video, is bad imho, because it simply replaces Kernel32.dll by a SP3 (russian) one ! Just get http://download.microsoft.com/download/c/6/b/c6babe1a-30f5-4f3e-a343-5167d9e2a914/WindowsXP-KB935839-x86-ENU.exe Append /b:SP2QFE to the installer to force the QFE version of the hotfix (as the GDR default version does NOT feature GetLogicalProcessorInformation). I guess this last Kernel32.dll hotfix was compiled "pre-SP3". It just works!