If you're talking about the taskbar.. then that is actually the quick launch shortcuts, those will never move unless you drag them around, add/remove them..
If you're talking about in your start menu then you are right, they do behave the way you're describing, they are listed chronologically, not by order of how much you use them. So the one you used Longest ago will show at top.. I believe, it seems to be
this way for me..
Anyway After some testing.. I removed one from the list, then opened the program up.. it put it in the middle of that list, so that's weird and i'm not sure..
There should be a line tho in the start menu, the ones above that line are programs that are "pinned" to the startmenu for whatever reason, you can do this to programs you'd like to see there, and you can remove the ones you don't want by right clicking
and doing "Unpin from Startmenu"
Also try right clicking the start menu itself... not one of the icons, if you can't find a good spot to do that, just right click your task bar
After rightclicking go to PROPERTIES (make sure you're on the START MENU TAB) You'll see the privacy section says "keep list of recently opened programs" and an option for documents
That is the list below the line.. try clicking customize, and see if you get anything you want.. I know you can change like how many programs are displayed in start menu as an example.
Good luck man!