The iTunes App Store, a digital store for iOS and Mac devices, features over 500,000 apps. Many of these apps are free and come in a variety of titles and genres including games and utility software. The App Store comes preinstalled on iPhone 4. When you're unable to download your favorite apps or connect to the App Store in general, verifying and inspecting your network connection can have you connected to a world of apps in no time.
The iTunes App Store relies on a network connection to connect to the Apple server, from which you download and install applications. When you're unable to access the iTunes App Store, the following error might appear on the screen: "Cannot connect to the iTunes store. An unknown error has occurred." This error might appear when you try to launch the App Store or if you're in the middle of a download. When the connection fails during a download, the application you're trying to install will stop downloading.
When you're unable to launch the App Store, it usually means the iPhone's network connection isn't working. If the device's connection to a wireless network suddenly drops or if the Wi-Fi signal becomes too weak or low, you'll lose the connection when you try to launch the App Store. This may happen if you move out of the Wi-Fi range. Other times, the connection problem may involve the wireless router you are connected to. If the router is behaving erratically or if the Internet service provider is experiencing technical difficulty, you'll experience Wi-Fi connection problems, which usually results in server connection problems when App Store tries to connect to the Internet. Connection problems might also occur if your 3G connection signal weakens.
If you lost a Wi-Fi signal because you moved out of the connection range, moving closer to the wireless access point should strengthen the connection. If the network you're connected to is problematic, verify other devices such as laptops are able to connect to the network. If they are not connecting, restarting or resetting the router by pressing the "Reset" button on the back of the unit may restore the network connection. If the problem persists, contact your ISP. Resetting the network settings from the "General" tab on the "Settings" page can also restore network connectivity. Keep in mind that if you reset the network settings, you have to locate and join the network again.
To improve your iPhone 4's performance, verify the iOS is up to date from the device's summary page in iTunes. If the device isn't up to date, clicking the "Check for Update" button will search for and install updates from the Apple server automatically.