Storing programs on the RCX..
When programs are transferred to the Cart they are stored in program slots.
Slots 1 and 2 are reserved for other programs and programs can be loaded into slots 3, 4 and 5.
Make sure when you run a program, you are running the program from the right slot. In other words if you load a program into slot 3, make sure you use the Program (Prgm) button to "cycle" through the slots until the display shows 3 at the right hand edge. Otherwise you could be executing some else's program.
To Run a program on the Cart, press the Green Run button.
Running a Program! Go Full Screen to see in greater detail?