Sync iPhone 4 to a new computer

itunes.

also look at sync settings on your phone, delete anything referencing your old computer.

its not a "once and done" deal. you can change sync devices.

First you need to authorize your PC with your iTunes account with iTunes if you haven't already done so. With your iPhone connected to iTunes and without syncing, at the iTunes menu bar go to File and select Transfer Purchases From - the name of your iPhone.
Besides what mentioned above, i like to share you a article about How to transfer or sync iPhone to new computer, which included transferring iPhone contents to computer/iTunes.
Hopefully this works for all of you like it just worked for me!

If you still have your iTunes media folder, you can copy that to your music folder. The library file should be immediately found. If not, you will have to select it by holding control+shift (I think. Someone correct me if i am wrong) and then opening iTunes. You will then browse to where the .it file is and select it. If your music doesn't show up, you will have to add it all to iTunes.

This topic has been closed by Pyree

Best answer selected by Nikorr.