Dumping memory from an operating system can be complicated and is not built-in feature. You also have to keep in mind that memory dumps are a snapshot in time of what is in the memory. The memory is constantly changing every second so having the right tool can be the difference between getting the data you need and having it lost forever. There are various tools for each operating system to accomplish memory dumps. Some tools are easier to setup and use than others and some tools are portable apps. I have provided links at the bottom of this post to all the tools I cover within this post.