Q: iphone 6s not recognizined by itunes ??  Is this a BUG ?

iOS: Device not recognized in iTunes for Windows - http://support.apple.com/kb/TS1538 and https://discussions.apple.com/message/29983567#29983567

I have this very same problem.  I own 3 Apple devices and none of them are recognized by iTunes latest update on either my PC or my labtop.  Cannot understand why Apple has not post another update.  I doubt we are the only two people experiencing this problem.

Reset your lockdown folder

That didn't work for me.  Ironically enough, the only device my frickin ITunes will see now is my big-pimpin, old school, 10 year old iPod classic. Go figure.  IPhone 6s, IPhone 6S Plus, and iPod Nano...none are seen by iTunes after the update.  So who was quality testing THIS release?

Try the following:

1. Open Control Panel > Device Manager
2. Plug in your device
3. Locate Universal Serial Bus Controllers > Apple Mobile Device USB Driver.
   It is also possible the device may show under Imaging Devices, Portable Devices or Other Devices or as an MTB USB Device.
4. Right-click and select Update Driver Software...
5. Click Browse my computer for driver software
6. Browse to C:\Program Files\Common Files\Apple\Mobile Device Support\Drivers or
                   C:\Program Files (x86)\Common Files\Apple\Mobile Device Support\Drivers
7. Click Let me pick from a list of device drivers on my computer
8. Click Apple Mobile Device USB Driver
9. Click Next, then Close and exit Device Manager

Or try iPhone, iPad, or iPod not recognized in iTunes for Windows - Apple Support

Failing that try a full tear down and rebuild of iTunes as set out in Troubleshooting issues with iTunes for Windows updates.

tt2

Thanks for the suggestion and steps. It did not work for any of my devices.  I'm stuck with uninstalling iTunes and then reinstalling. I'll probably try a previous version since this one is clearly flawed.

See iTunes installers for download links. If you're rolling back from 12.3.3.17 to 12.3.2.35 then you'll also need to roll back the library database in the way described in Empty/corrupt iTunes library after upgrade/crash.

tt2