iPhones and Windows PCs aren't exactly built to work together. Don't get me wrong, Microsoft and Apple made it possible for the two devices to be connected and interact with each other, but it wasn't exactly the main concern for either of them. This means that from time to time, especially if you don't want to use iTunes, the iPhone that you've just plugged in might not show up in the My Computer window. In case you're dealing with this kind of issue, here's how to troubleshoot them:
If you're connecting the iPhone for the first time and there's no window popping up on your PC, you should start out by trying a different USB port, preferably one that you're sure is working. In case you've done that and nothing happened, I recommend verifying that you're using a certified Lightning cable capable of data transfer. In some cases, the cheaper cables that you get from small stores or websites can only charge your phone, but cannot transfer information and that might be way your iPhone isn't detected by the PC. Lastly, check if your USB ports are functioning properly; here's a short guide on how to fix the USB ports in case it's necessary.
In case you're sure that your problems aren't caused by the hardware, the next logical step is to eliminate any possible software issues. This is actually quite effortless, but it may also take a while. All you need to do is to make sure that there's no Windows or iTunes update that you haven't installed. Simply launch the iTunes app, then go to Help, click on Check for Updates, then simply follow the steps the application gives you. To make sure your Windows is up to date, click the Start button, then go to Settings-->Update & Security and press the big Check for Updates button. In case you've found updates for either iTunes or Windows, restart the PC after installing them. Lastly, when you connect the two devices, you should see a prompt on the phone asking you if you trust the PC; make sure that you tap the Trust button.
If everything else fails, as a last-ditch effort you should try updating or reinstalling the drivers for your iPhone. Right-click the Start menu, then choose Control Panel and go to Hardware and Sound-->Devices and Printers. Next, look for an Apple iPhone entry in the Unspecified category, right-click it and press Properties. In the new window that opens up, click over to the Hardware tab and once again press Properties. Finally, go to the Driver tab, click Update Driver, then instruct your PC to look online for a newer version. In case nothing happens, uninstall and reinstall your current drivers and everything should be fine.
There you have it folks. Now you know why your iPhone may not show up in the My Computer window and how to fix these issues. In case you run into an error telling you that the iPhone has been found, but couldn't be identified, here's how to help iTunes identify your iPhone.