Connecting an old Iphone to Itunes

I have an old iphone that I no longer use. It works just fine, and I have wifi enabled and can browse the web, youtube, connect to the itunes store, whatever. I would like to load it up with some music and use it as an ipod, however I cannot get my computer to recognize it. It will not update past IOS 7.1.2. I am running windows 7. The device manager sees it as "unknown device" I have tried changing the driver to the usbaapl64 in the apple drivers folder, but the computer still cannot recognize the iphone. I have uninstalled and reinstalled itunes, restarted the Apple Mobile Device service, unplugged and replugged, tried different cables, everything I can find online that is recommended I have tried. There doesn't seem to be a reason why the iphone won't connect to my computer other than it's just old. Are there old drivers some where online I can try?