You may first transfer your iphone 4 contacts to your computer. and that may right there in your “Address Book” on your computer. If “Address Book” is in your dock, the icon is with “@”symbol. If not like that, go to Applications in Finder and do a search for “Address Book”
Next time, do an Address Book export just to have another back-up if you are not automatically backing up using Time Machine, your iDisk, or whatever. If you back up to a file on the same computer, copy it to an external drive.
There're so many trouble transfering from apple products to PC, As a lazy person I personally prefer using a simple software iPhone Transfer Contact, why bother?!
