Setting the start position just means it will appear in the position you tell it to (via the Location property). In order to do this, when your program closes you need to save the Location to a file of some kind, then when your program starts up again, read that file and set the Location accordingly.
How you save it is up to you, but you can look into using the
Settings class or you can just write it to a file yourself.
There is a few gotchas that you should be aware of though. The most important one is that when Windows minimizes your program, it actually sets the Location to something like -32000, -32000. When you go to write your program you'll need to check to see if it's minimized and possibly restore it before you get the Location. Another thing to be aware of is having a system with multiple screens, then loading your program up with the same config in another screen configuration (physical dual screen and remote desktop single screen is a great example). The windows desktop is a big canvas where you only see what your screens show, so if your app starts up and sets a form position to a location that's off your desktop, you just won't see the form. The best idea is to get the area of your screens using the
Screen class and make sure your form will be visible on it. If not, start it up in the default position.
I hope that helps :)