If your PC does recongnize your iphone but no your Itunes try this:
-Go to device administrator on your PC.
-Search for your device (Apple Iphone), do right click on it and choose "update Software controller".
-Choose the second option "Browse my computer for driver software".
-Then choose the second option again again "Let me pick from a list of device drivers on my computer"
- Choose "Use Disk" option. Click Browse and navigate to C:\Program Files\Common Files\Apple\Mobile Device Support\Drivers.
- Double-click the "usbaapl" file. If you have a 64-bit version of Windows, this file will be called "usbaapl64". If you don't see "usbaapl64" here or if there isn't a Drivers folder, look in C:\Program Files (x86)\Common Files\Apple\Mobile Device Support\Drivers.
-Click open, then next, and then finish. This will install the driver.
If a message says that the software you're installing "has not passed Windows Logo testing," click Continue Anyway.
I hope this little guide helped you
PD: If it doesn't, restart the Apple Mobile Device Service here