If you are going to change your iPhone or just want to take backup of your iPhone contacts, here is a simple way to export your iPhone contacts as csv file in Windows 7 and you can open this csv file inExcel. You just need your iPhone and iTunes running in Windows7.
Export iPhone contact as CSV file or to Excel
Download and install iTunes, after installation Run iTunes.
Connect your iPhone with computer using data cable.
On the safe side backup your device first, Right-click on your device and select “Back Up” (in-case of any problem with iPhone Contacts you can restore your device later).
When iTunes finish the back up process, Click on “Info” tab
Click on “Sync Contacts with” check box, select “Windows Contacts” from drop down menu and click “Apply” or “Sync” button
Press “Windows + R” keys form keyboard to open “Run” window and type “wab” in “Open” filed and hit OK
Click on tiny arrow and select “Export” as shown below
Select “CSV (Comma Separated Values)” option and click “Export” button
Click on “Browse” button, choose location to save iPhone contacts as csv file
Select iPhone contacts fields that you want to export and hit “Finish” button
You will see this message if iPhone contacts exported as csv file successfully, hit “OK” button.
Now you can use this csv file to import iPhone contacts in any other application or device or you can open this file in Excel to view all iPhone contacts.