Keeping up with your appointments doesn't have to be limited to your desktop computer's Windows Calendar. You can transfer the appointments saved in Windows Calendar on your computer to your iPhone to allow access to your important calendar dates with you at all times.
Connect your iPhone to your computer with the iPhone's USB cable.
Open iTunes and select your iPhone device from the source list (the column on the left side of the window).
Click the "Info" tab at the top of the screen when the "More Info" screen appears.
Select "Sync Outlook Calendars."
Click "Apply" in the bottom-right corner of the screen.
Click "Eject" next to your iPhone device's name when the sync is complete.
Things You'll Need
Apple iTunes software (latest version)
iPhone USB cable
iPhone running the latest iOS software
Outlook (Express, 2003 or 2007)
If you are syncing your iPhone with iTunes for the first time, run through the setup that will allow you to sync automatically. With this installation, you also name your device.
Make sure you have the most recent version by selecting "Help" from the iTunes menu bar and "Check for Updates."
Your Windows Calendar information must be stored in an Outlook-compatible calendar application.