Belows shows the steps for backing up your iPhone contacts.
- Open iTunes
- Plug in your phone to the computer
- Open the program “Address book” via Start | Programs | Accessories.
- Within iTunes click on the phone icon on the left.
- Click on Info, and under “Contacts” select “Sync contacts from” and then choose “Windows address book” from the drop down menu.
- Select All contacts
- At the bottom right of iTunes, click “Sync” It will ask you if you want to merge or replace. Make sure you select MERGE or it will delete your contacts on the phone.
Once done check your check your Windows Address Book and all your contacts should be in there.