Helping people with computers... one answer at a time.
When more memory is added to a computer, most of the system will automatically use it without the need to adjust settings on your machine.
After installing more memory, will I need to reconfigure or will my computer notice and add the memory on it's own?
Thankfully, this is one the computer usually gets right.
You didn't indicate which operating system you use, but unless there's a problem with the memory you're adding, most the system will simply notice that there's more memory and use it automatically.