The most common reason why your iPhone won’t connect to iTunes or its not communicating with your computer is that the device driver isn’t working properly; or the one of the device drivers is missing from your computer.
On a PC, the first thing you need to do is to open Device Manager. You’ll find Device Manager in Control Panel, but the easiest way to do this is to click on the search bar on your computer and type “Device Manager”.
After you open Device Manager, look for Universal Serial Bus controllers and click on the small triangle icon just to the right. A dropdown menu will open and you should see Apple Mobile Device USB Driver.
If you see Apple Mobile Device USB Driver but your iPhone won’t connect to iTunes, the driver probably needs to be updated or repaired. Right-click on Apple Mobile Device USB Driver and three options should appear: Update Driver Software…, Disable, and Uninstall.
If you see an option to Enable, click that and your problem should be solved. At some point, the driver was disabled, so enabling it again will fix the problem. if you don't see enable read below:
Uninstall And Reinstall The Driver
I have found that uninstalling and reinstalling the driver is the easiest way to solve driver issues. The driver will only appear if your iPhone is plugged into your computer, so make sure your iPhone is plugged in before you look for this driver.
Click Uninstall and Windows will remove the driver from the list of Universal Serial Bus controllers. Next, unplug your iPhone and plug it back in. When you do this, your computer will automatically recognize your iPhone and reinstall an up-to-date version of the driver.
An out-of-date driver is a very common reason why an iPhone won’t connect to iTunes, so this should fix the problem. Open iTunes and look for the iPhone icon to see if your iPhone is connected. Make sure to look at your iPhone and click “Trust” to make sure it shows up.
It’s very important that you tap Trust on your iPhone, or it won’t communicate with your computer at all. At this point, if your iPhone is showing up in iTunes, then you’re all set! If your iPhone still doesn’t show up, keep reading.
Choose The “Update Driver Software…” Option If You Can
If you choose Update Driver Software… after right-clicking on Apple Mobile Device USB Driver, you’ll see two options: Search automatically for updated driver software and Browse my computer for driver software.