PowerPoint supports a handful of command-line parameters. Use these to create special Windows shortcuts (right-click the desktop | New | Shortcut) or to perform PowerPoint tasks quickly from the command prompt.
Of course you need to modify the commands based on where you installed PowerPoint:
Open a presentation "x:\Program Files\Microsoft Office\Office11\powerpnt.exe" "filename.ppt"
Print a presentation "x:\Program Files\Microsoft Office\Office11\powerpnt.exe" /p "filename.ppt"
Start a presentation in slideshow "x:\Program Files\Microsoft Office\Office11\powerpnt.exe" /s "filename.ppt"
Another way to start a presentation directly in slideshow is to simply change your PowerPoint file's extension from PPT to PPS. In other words, rename filename.ppt to filename.pps .
Then, when you open the PPS file, by double-clicking it for instance, PowerPoint sees the PPS extension and launches directly into slideshow. This can be a useful way to distribute presentations.
Inside PowerPoint, you can also save as a PowerPoint Show, but all that does is do the renaming for you.