If iTunes cannot access the iTunes Music Store, it might display this alert message:
"Cannot connect to the Music Store. An unknown error has occurred."
Click on the description below that most closely matches your Music Store situation:
I have been unable to connect to the iTunes Music Store...
for less than 24 hours.
for more than 24 hours on a Mac.
for more than 24 hours on Windows.
I have never been able to connect to the iTunes Music Store on this computer.
I have been unable to connect for less than 24 hours
Try quitting iTunes and reopening it. If the issue persists, it's possible the store is temporarily unavailable for maintenance. Try again in a few hours. You might want to check the iTunes Music Store discussion board to see if a connection issue is impacting many other iTunes Music Store customers.
iTunes Music Store Discussion Board (Mac)
iTunes Music Store Discussion Board (Windows)
I have been unable to connect for more than 24 hours on a Mac.
If you haven't been able to connect to the iTunes Music Store for more than a day—and other customers on our discussion boards aren't experiencing similar issues—a software or ISP configuration issue may be blocking your access to the iTunes Music Store.
Your copy of the iTunes application may be out of date.
If iTunes is out of date, it will not be able to connect to the iTunes Music Store. You can download the latest version of iTunes from our website:
You may need to reset your keychain.
Connection errors are occasionally caused by keychain issues. Click here to find out how to use Keychain First Aid to resolve this issue.
You upgraded to a high-speed or wireless Internet connection.
A new DSL or cable modem, or even a router, could be the culprit. These devices allow your computer to access the Internet at a much higher speed, or route your connection to multiple computers. However, they can also expose your computer to hackers. To help prevent this, manufacturers of these products often install firewalls to prevent hackers and viruses from compromising your system. Although this layer of protection is beneficial, there are occasions when a device may determine that the iTunes Music Store is a threat to the computer. If this is the case, you will need to configure these devices to allow iTunes to access the Music Store. Contact your ISP or the device manufacturer if you need help configuring your device.
You switched to a new ISP.
If you didn't install new networking hardware, your ISP may be blocking access to the iTunes Music Store. Let your ISP know about this document which can help your them configure their servers to allow iTunes Music Store traffic through.