Modern computers generally recognize external hardware automatically. Sometimes it may happen that the computer does not recognize an iPhone, iPad, iPod etc. This may happen after the user has the updated iTunes software. During the update process some of the components may be damaged or lost completely. It could also be due to problems in hardware like USB ports, cables or iPhone. The solution is to reset the iPhone and reinstalling iTunes. One should also make sure that all of the important components are installed successfully and are working fine.
It may happen that after an iTunes update, the iPhone or firmware is no longer recognized by your PC. There are several possibilities.
You should know that the drivers for the iPhone, iPod Touch and iPad are included with the iTunes installation, and within the iTunes.exe folder a number of applications such as QuickTime, Apple mobile device support, etc.
During updates or other changes made to the PC, it may happen that one of these components is lost or not installed correctly.
Of course, another reason could be a hardware issue such as problems with cables, USB ports, or the iPhone itself