When you click Compile or Compile and Program the current active/open file will be compiled and assembled and the resulting .hex and .lst files etc will be in the same folder as the source file. MCS knows the path to the source file because you told it that when you opened the file.

When you click Compile MCS automatically invokes the compiler and passes along the filename (and path) to whatever file you currently have open as well as the processor selected for that particular file. If you have several files open, in different tabs, and the files are in different folders the .hex file will be put in the folder for the particular file you're compiling.

Does that make sense?

/Henrik.