I have this program where I take in an excel file and manipulate it, I currently have it saving to a specific folder. Is there anyway I can have that file open on the user's computer after the program has executed.
By "Open that file" you mean "Launch Excel with that document opened", yes?
You would use Runtime.exec() to run a command like "cmd.exe /c start foo.xls" . The classic article on Runtime.exec() -- which you absolutely should read! -- is here. It will tell you exactly what to do, and what not to do.