I've created a program and would like to release it, but am currently struggling with dll dependency issues. How can I create a msi installer package that will properly install .dlls? Every solution I've found online so far has created msi packages that only include the exe.
Short Answer: Generally, the most common runtimes are:
Java,Visual Studio C/C++ Runtime,.NET Framework. Try installing these on a clean virtual and try launching your application. Debugging application launch check-list.
Modern Deployment: Many Microsoft runtimes that we used to deploy are now part of Windows. An exception is the Visual Studio C/C++ runtimes. I am not sure why they are not just included in Windows at this point. In general you should not pick single dll files to deploy, you need to locate a merge module, a setup.exe or an MSI to deploy the runtime. Commercial tools have features to help you download such bundles.
Setup: The basic, general steps to create a setup are described here: How to create a windows installer for multi language program with outside dependencies?
Specific Runtimes: One can generally determine runtime requirements by looking at the application files (experience - trained eye), looking at the application GUI (visual clues), checking dependencies using dependency scanner tools, talking to the developers of the application, checking file properties of files you find to depend upon (Company name is a good clue), etc... Then you verify and test this on a clean, virtual machine. You keep installing runtimes manually until your application works. In the section "The Complexity of Deployment" here you can find a listing of common runtimes and technologies.