John,

>The size of the exe is now approximately 18 Megs and contains four modules that are related but have different functions.

Others will give you better answers on possibly splitting up your EXE, but I wanted to point you to thread#290673 titled "Tips for Reducing EXE size", in case you haven't tried those tips for shrinking the EXE. You may find other appropriate threads by searching on "size EXE" or "large EXE", etc.