First of all, open your Microsoft Entourage on your PC. Then, select the option ‘Preferences’ from the drop-down menu of ‘Entourage’ which is visible at the top of your screen.
Now, select ‘Sync Services’ from the column of ‘General Preferences’. After that, check the box ‘Synchronize contacts with Address Book and .Mac’. It will automatically send all your contacts to the Mac’s Address Book app which will sync them to your iPhone through the iTunes.
After opening iTunes on your PC, connect your iPhone by the USB cable. Then, click on the iPhone icon in the ‘Devices’ and you will see ‘Info’ tab at the top of the window. Select the ‘Info’ tab.
Then, check the box ‘Sync Address Book contacts’ which is in the ‘Contacts’ field and select the contacts which you want to sync (you can either sync all the contacts or only some specific ones).
Now, click on the ‘Apply’ button which is given in the lower right corner of your iTunes in order to apply the changes. Then, click ‘Sync’.
iTunes will notify you that whether it is safe to eject the iPhone or not. After seeing the sign, you can disconnect your iPhone as the contacts have been synced in your iPhone’s Contacts list.