How can I upgrade iOS 5 to iOS 7 (iphone 4)?

Howdy ValeryGL,

It sounds like you need to know how to update to iOS 7 on your iPhone 4. I would connect the device to a computer with iTunes and update it there, that way you get the latest supported version of the software:

Update the iOS software on your iPhone, iPad, or iPod touch

Update your device using iTunes

If you can’t update wirelessly, you can update with iTunes. If your computer uses the Personal Hotspot on the iOS device that you’re updating, connect your computer to a different network.

1. Install the latest version of iTunes on your computer.
2. Connect your device to your computer.
3. Open iTunes and select your device.
4. Click Summary, then click Check for Update.
   
5. Click Download and Update.

If you get any sort of error when you try or anything like that take note of this section:

If you see error messages in iTunes or need more space to update

Get help when you see error messages while updating your device with iTunes. Or if you need more space for an update, you can delete content from your device manually.

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