Ensure the device is connected to the computer via the supplied USB cable.
Launch BlackBerry Desktop Software. From the Windows desktop, navigate Start > All Programs (Programs) > BlackBerry > BlackBerry Desktop Software.
From the left menu, click Organizer.
Select Configure settings.
Select Calendar Selected when checked.
Select the appropriate desktop app (e.g. Microsoft® Outlook) then click Next. The list of Available desktop apps may vary.
Select one of the following synchronization options then click Next: If using One way sync and if necessary, select (check) Replace all data in the target app to overwrite the existing data when a synchronization is performed.
Two way sync
Changes are synchronized to the device and desktop app.
One way sync from Device
Changes are synchronized to the desktop app only.
One way sync to Device
Changes are synchronized to the device only.
Configure synchronization options as appropriate then click Next. Available options may vary depending upon the desktop app (e.g. Microsoft® Outlook, Windows Mail, Yahoo!) being configured. If configuring a web-based desktop app (e.g. Yahoo!), click Options, enter the appropriate ID and Password then click OK.