Now, We can re-download purchased apps from app store easily. Just follow the instructions:

1. Open the App Store on your iPhone or iPad.
2. Make sure you are signed in with the same account used for the past purchase.
3. For iPhone, Tap Updates from the bottom navigation bar, then tap Purchased.
   

   For iPad, Just tap on Purchased from the bottom navigation bar. 

   

4. Find the app you want to re-download in your Purchased tab, Tap the download button, The app will start downloading now.

With Airport Express, You may run Toslink cable from the wall to you HIFI system and configure it to use Airtunes or AirPlay. Then you may play the music on iTunes and listen on your HIFI system.

Another way is via AppleTV. With Apple TV, Connect the optical out to your AMP and then pull data from a shared iTunes library on your network, and control the music with the remoter on your TV.

Just enjoy iTunes music on your HIFI system Now!

The easist way to redownload the apps is redownload them all by iTunes.

1. open itunes, and make sure you are logged in with the right account which purchased the apps.

2. Click menu "Store | Check for Available Downloads…", iTunes will download all of missed apps for you automatically.

Another way is to download specified app. Here’re the instructions:

1. Open iTunes.

2. Find the app in App Store and click the "BUY" button

3. Click "Buy" button in the popup button

4. iTunes will inform you that the app has been bought and will download it again. Click "OK" button then iTunes will download the app for you.

Now, All of missed apps are back to your iTunes, Just Sycn them to your iPhone, iPad or iPod.

How to upgrade to latest iOS for my iPhone, iPod or iPad?

It’s easy. Just 3 steps. Here’s the guide:

Step 1: Connect iPhone to computer
 
Before it, Make sure you have the latest version of iTunes. The latest version of iTunes can be downloaded from http://wwwitunescomdownload.com/itunes-download or official website: http://www.itunes.com/download.

Step 2: Open iTunes

Open iTunes, Then select your iPhone under Devices in the Source List on the left panel.

Step 3: Start Updating

In the iPhone summary panel, click "Check for Update" button.

Then the update confirm dialog will open. Click "Download and Install".

Don’t disconnect your iPhone from computer and just wait for 2-3 minustes, The latest iOS will be downloaded and updated.

Now your iPhone is running with latest iOS. Just enjoy the new features!

But, If your reinstall your iTunes or break down of your hard drive, the automatic sync is dangerous. By synchronizing your iPod or iPhone with a damaged or deleted iTunes library you risk to erase the entire contents of your iPhone/iPod. In case of a problem or if you doubt about the contents of your iTunes library, "Manually Manage Music and Videos” mode will help you to prevent content loss.

How to set up the “Manual iPod management”?

Disconnect iPod/iPhone from PC at first, then open iTunes and go to Edit>Preferences>Devices and check the box "Prevent iPods and iPhones from syncing automatically" and choose OK.

Then connect iPod/iPhone again. Choose your device in the left column and select the first tab which name is “Summary”. Check the option “Manually manage music and videos” and confirm with “Apply”. Now you may manage your iPhone or iPod contents manually without any risk of losing your favorite music and videos.

There’re many new features with the iTunes 9, Here are some:

• Improved store navigation, including persistent navigation menu.
• Full window iTunes store. For times when that sidebar is just too much.
• Previews from anywhere in the store – don’t have to drill down to preview.
• iTunes LP includes lyrics, liner notes, video, photos and “more.”
• iTunes Extras. It’s like DVD extras, but with iTunes. Not clear if it includes director’s commentaries, but let’s hope.

Go to http://www.apple.com/downloads, Enjoy iTunes 9 now!