Using the BlackBerry Desktop Restoration feature
Only works if you have backup data to restore on the handheld device.

Install and open the BlackBerry Desktop Manager on your computer.

Set your Blackberry on the cradle properly and you should see the status bar change to connected.

Double click on Backup and Restore.

Click on Options

Select Automatically backup my handheld every 7 days.

Select backup all handheld application data.

Click on OK.

 Click on Backup.

The default location for the backup file may be My Documents\Blackberry 6750 backup\. If different browse to the location where you have stored the backup file. Select the backup file and click on Open.

A warning box will be displayed for you to confirm restoration. If desired click OK.

When the restoration process is complete, click on Close.