I made a program in Visual Studio 2010 on Windows 7 64-bit. When I try to run it on Windows XP 32-bit I got message that msvcr100.dll is missing. When I try to copy that fil
Linking the runtime libraries statically should help. Go to Project Options -> C/C++ -> Code Generation -> Runtime Library and change the value to Multithreaded or Multithreaded Debug and recompile. This way your application shouldn't depend on the runtime DLLs.
Also don't forget to build a 32bit executable.