Background ImgeCFG is a utility that probably does a lot of things (I cannot find any official documentation), but the only reason I use it is to fix old games (UT99 for example) which have problems on multicore/multicpu systems. It does so by assigning an executable to specific logical CPUs permanently (by modifying the .exe file, so backup the original incase you want to restore it). This utility will work in pretty much any modern Windows operating system (2000/XP/Vista/7) and it is meant to be used on computers with multiple CPUs, multiple cores, or Hyper Threading. Use ImageCFG will work from any directory, but for ease of use, it can be placed in %systemroot%\system32 (or C:\Windows\system32) and %systemroot%\system32\dllcache (or C:\Windows\system32\dllcache). Doing so will make imagecfg a system command (run it from anywhere in any cmd window or the run dialog). This article assumes you have done so. The -u option sets a specified executable to only run in "uni-processor" mode on multi-processor systems. This is probably optional but I run it anways. The -a option sets a process affinity mask (hexadecimal value) to the specified executable, so that it always runs using the specified CPU. You can also add up the bits to set multiple CPUs (thanks LigH). Examples (hex = decimal = CPU): * 0x01 = 1 = CPU0 * 0x02 = 2 = CPU1 * 0x04 = 4 = CPU2 * 0x08 = 8 = CPU3 * 0x10 = 16 = CPU4 * 0x20 = 32 = CPU5 * 0x40 = 64 = CPU6 * 0x80 = 128 = CPU7 * 0x0f = 15 = CPU0, CPU1, CPU2, and CPU3 (1+2+4+8 = 15) Examples The following examples will use UT99 from Steam to fix the speed issues I have been experiencing on my FX-60 (AMD dualcore) computer running Windows 7 Ultimate 64bit: imagecfg -u "C:\Program Files (x86)\Steam\steamapps\common\unreal tournament\System\unrealtournament.exe" * Probably optional, but the above sets the exe to use only one CPU. imagecfg -a 0x1 "C:\Program Files (x86)\Steam\steamapps\common\unreal tournament\System\unrealtournament.exe" * Sets the exe to use CPU0
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