When you are compiling and linking programs that use the ILOG CPLEX Parallel Optimizers, it is especially important to review the relevant flags for the compiler and linker. These are found in the makefile provided with UNIX distributions or in the sample project files provided with Windows distributions. It is also a good idea to review the section on Using Parallel Optimizers in the ILOG CPLEX User's Manual for important details pertaining to each specific parallel optimizer.