Did you try doing a Reset (restart) on the iPod
Learn how to reset your iPod - Apple Support
and if that does not help, a Restore using iTunes. The Restore erases the iPod, reinstalls its software, and sets it to default settings. If the iPod still appears in iTunes when connected, the Restore button is on the iPod's Summary settings screen.
Use iTunes on your Mac or PC to restore your iPhone, iPad, or iPod to factory settings - Apple Support
If that does not help, because the iPod has a hardware problem that prevents the click wheel from working, and you want to replace it... Your options:
- Upgrade Windows to 7 or later.
- Get a (new or recent) Mac.
- Buy an older iPod. For example, the 2012 version of the 7th gen iPod nano is functionally the same as the 2015 version (mostly new color choices), but the older version supports back to Windows XP (SP3) and Vista. This web page provides details for all iPods
http://www.everymac.com/systems/apple/ipod/index-ipod-specs.html