First:
iTunes: Fix iPhone or iPod Not Detected in Windows 10
next try
iPhone, iPad, or iPod not recognized in iTunes for Windows
- I would start with
Removing and Reinstalling iTunes, QuickTime, and other software components for Windows XP
or
Remove and reinstall iTunes and related software components for Windows 7 and later
- New cable and different USB port
Also see:
iPod not recognised by windows iTunes - ASC
Troubleshooting issues with iTunes for Windows updates
- Try on another computer to help determine if computer or iPod problem
Forgotten Screen-Lock Passcode
Connect the iOS device to your computer and try to make a backup
iOS: How to back up
Then restore via iTunes. The iOS device will be erased. Place the iOS device in Recovery Mode if necessary to allow the restore.
If recovery mode does not work try DFU mode.
How to put iPod touch / iPhone into DFU mode « Karthik's scribblings
For how to restore:
iTunes: Restoring iOS software
To restore from backup see:
Restore your device from an iCloud or iTunes backup - Apple SupportIf you restore from iCloud backup the apps will be automatically downloaded. If you restore from iTunes backup the apps and music have to be in the iTunes library since synced media like apps and music are not included in the backup of the iOS device that iTunes makes.
You can redownload most iTunes purchases by:
Downloading past purchases from the App Store, iBookstore, and iTunes Store
If problem what happens or does not happen and when in the instructions? When you successfully get the iPod in recovery mode and connect to computer iTunes should say it found an iPod in recovery mode.
