The Nano uses different drivers than iOS devices like the iPod touch
Run this to help if it identifies the cause
Have you tried on another computer to help determine if you have a computer or iPod problem?
Yes, I'd already done Removing and reinstalling iTunes, QuickTime, and other software components for Windows Vista or Windows 7, to no effect. I've just run the Diagnostics Sync Test, result was "No iPad, iPhone or iPad found", details below:
Microsoft Windows 7 x64 Home Premium Edition Service Pack 1 (Build 7601)
Gigabyte Technology Co., Ltd. Z68X-UD5-B3
Apple Application Support 2.3.6
iPod Updater Library 11.1f5
CD Driver 18.104.22.168
CD Driver DLL 22.214.171.124
Apple Mobile Device 126.96.36.199
Apple Mobile Device Driver 188.8.131.52
Bonjour 184.108.40.206 (333.10)
Gracenote SDK 220.127.116.112
Gracenote MusicID 18.104.22.168
Gracenote Submit 22.214.171.124
Gracenote DSP 126.96.36.199
iTunes Serial Number 00C7BCA00CFCCB40
Current user is not an administrator.
The current local date and time is 2013-11-12 23:35:26.
iTunes is not running in safe mode.
WebKit accelerated compositing is enabled.
HDCP is supported.
Core Media is supported.
Video Display Information
NVIDIA, NVIDIA GeForce GTX 560 Ti
**** External Plug-ins Information ****
No external plug-ins installed.
iPodService 188.8.131.52 (x64) is currently running.
iTunesHelper 184.108.40.206 is currently running.
Apple Mobile Device service 220.127.116.11 is currently running.
**** Device Sync Tests ****
No iPod, iPhone or iPad found.
Have tried it on two other systems - one Windows 7 running iTunes 18.104.22.168 and one Mac running iTunes 11.1.1(11) - both systems recognised the iPod and attemted to begin syncing. Have used two different cables and have used different USB connectors on my PC, no change in the problem. Can't see any foreign material in iPod dock connector, but if there was then I assume that the connections to the other two PCs would have been successful.
YOu previously said "Have tried it on two other systems - one Windows 7 running iTunes 22.214.171.124 and one Mac running iTunes 11.1.1(11) - both systems recognised the iPod and attemted to begin syncing. "
Just what happened then? Did the syncing stop? What was displayed on the starus bar of iTunes?
Without knowing that I can't say whther to reinstall WIndows or restore/erase the iPod.
"Reset All Settings" willhave no effect on your problem
What do you mean by formatting your PC?
I have a similar issue to yours - I was able to sync my iPod Touch 3rd Gen and iPad Retina to iTunes fine. My last successful sync was on Oct 15 2013. Then, I upgraded my PC by switching to an SSD and doing a clean install of Windows 8. Copied my iTunes library, and installed iTunes 126.96.36.199, and now neither the iPod or iPad are recognized by iTunes. WIndows does recognize both devices.
I have tried every solution on the Apple support site, including reinstalling iTunes, stopping/starting the service, etc. I've tried different cables, different USB ports, nothing seems to make a difference. There are plenty of other users with the same issue apparently, and most seem to have started with either iTunes 11.1.2 or 11.1.3.
I figured out my problem... the Apple Mobile Device USB driver was not installed. Once the driver was installed, the iPod was recognized in iTunes.
Instructions here: http://support.apple.com/kb/ts1538