How do you stop run once from run on computer start in Windows 8.1?

To stop a program from running at startup in Windows 8.1, press Ctrl + Shift + Esc to open the Task Manager. Go to the "Startup" tab, find the program you want to disable, right-click it, and select "Disable." Alternatively, you can also use the System Configuration tool by typing msconfig in the Run dialog (Win + R), navigating to the "Startup" tab, and unchecking the program you wish to disable.