Maybe it is already running, that is usually what happens when you try to launch a secondary occurrence of a program that only allows one occurrence. Right-Click on the task bar, and click "Task Manager"-->then click the Processes tab. Scroll down the list to see if it is running when you boot your PC.
It could also be a deprecated shortcut.
Also, if you have moved the folder, for example from C:\Local Disk\Program Files\SpeedupMyPC to C:\Local\SpeedupMyPC Disk\ , I believe you might experience such behavior.
Hope this helps,