Q: When I go to software update it show checking for update

Hi swekrit,

If you are having issues with updating your iPod, I would suggest that you troubleshoot using the steps in this article - 

Resolve iOS update and restore errors in iTunes

Thanks for using Apple Support Communities.

Best,

Brett L 

Hi swekrit,

The error 9006 is typically due to security software on your computer. See this article for resolution -

Resolve iOS update and restore errors

Thanks for using Apple Support Communities.

Best,

Brett L 

Hi swekrit,

Thank you for using Apple Support Communities. Due to the nature of the issue you described you may find more information by using another one of Apple's support resources - https://getsupport.apple.com/GetproductgroupList.action.

Brett L