When you first create a System, the software uses the System name as it's file name for intial saving more for default purposes than anything.
This is similar to what Microsft does in word files. If you write a letter that starts off with "Dear Bob" it will offer "Dear Bob.docx" as the file name. Should you later open that word file and change the letter to say "Dear Jim", the name of the file will still remain "Dear Bob" even though you've changed the words contained in the file.
To give the file a new name, go to File>Save System As and input the new name. Bear in mind you will continue to see the old/original file if you do some Windows Exploring.
Also if you give the file a new name, then if using a Profile, you might want to close the original file and save the Profile. (Profiles get file names, rather than system names).