Over 40.
This is assuming that you have your computer going, as switching it on, and Windows starting, is in fact starting a program.
Some of the below methods in later versions of Windows do not work but have usually been replaced by other methods.
Other than remotely controlling another computer I have not considered internet based programs as being Windows programs, otherwise there could be millions of way of starting programs.
- Double Clicking on a desktop Icon
- Press Enter on a selected item
- Right Clicking a program and selecting Open
- From All Programs
- From an item on the taskbar (Win7) or the quick launch bar (prior to Win 7)
- From recently used programs from the Start Menu
- By right clicking a program and selecting Run as Administrator
- Right clicking on a file and selecting Open With
- From the System Tray
- Typing the program name in Search Programs and files at the Bottom of the Start menu (Win 7)
- From the Run function in the Win XP start Menu
- By Clicking on a recently used file in the Win XP start menu
- By right clicking on a Program in the start menu that has a Jump List and clicking on it (Win 7)
- By right clicking a Program on the Task Bar and clicking on a Jump List item (Win 7)
- By holding down the Windows Key and pressing a number that represents the item in the task bar (Win 7)
- By holding down the Windows Key and pressing a letter (Eg. Win Key + E Starts Windows Explorer)
- Hold down the Windows Key and Press R and then enter a program name
- Hold down the Windows Key and Press O which opens the Ease or Access Centre and then select a program from it
- Hold down the Windows Key and Press X which opens the Windows Mobility Centre and then select one of its programs
- Press a hot key combination that has been set up in a shortcut to start a program
- From the Control Panel
- By double clicking a file in Windows Explorer
- By Dragging a file to a Short cut
- By typing the programs name from a DOS prompt
- From within a program that allows starting of other programs
- From within Windows Help and Support
- By running a Batch File (.bat)
- By placing a program in the Startup folder in the start menu (Starts when Windows Starts)
- By talking to the computer when Windows Speech Recognition is activated
- Via a program that starts programs at a predetermined date and time
- Via an event happening. eg's data changes, another program stops, a temperature is exceeded
- Via another computer that is networked to other computers
- By touching or clicking on a tile (Win 8)
- Via the Charm Bar (Win 8)
- For programs started from contextual menus swiping down from the top or up from the bottom of the screen (Win 8)
- From the Apps List (Win 8)
- From Recently Added in the Win 10 Start Menu
- From Setting in Win 10
- By double clicking on a recent file in the Win 10 File Explorer
- By showing the Jump list of a program on the start menu (Win 10) and the clicking a file in that list
- By right Clicking on start and then click on an item in the list
- From God Mode (a folder named GodMode.{ED7BA470-8E54-465E-825C-99712043E01C}) on the desktop (Win XP upwards)