# MATLAB: Am I unable to use an S-function Builder block in Simulink 5.0 (R13) that was compiled on a different machine using MSVC

Why am I unable to use an S-function Builder block in Simulink 5.0 (R13) that was compiled on a different machine using MSVC?
I have an S-function Builder block that I compiled on one PC using Microsoft Visual C 6.0. It works on that machine. But if I copy my model and all other files, including the .dll file, to an identical PC that does not have Microsoft Visual C installed, I cannot run my model. If I try, I receive the following error:
 Unable to load mex file: E:\1290049\timestwo.dll. The specified module could not be found. ??? Invalid MEX-file