My itunes no longer recognizes my nano

Hello Tammie.
We're glad to help you with that.
Please refer to this article (https://support.avg.com/SupportArticleView?urlname=Disable-AVG-Antivirus) for detailed instructions to temporarily disable your AVG Internet Security program and check on your issue.
Let us know if you need further assistance.

I am using windows 10.  I have tried everything except disabling AVG security software

Hello Tammie.
We're glad to help you with that.
Please refer to this article (https://support.avg.com/SupportArticleView?urlname=Disable-AVG-Antivirus) for detailed instructions to temporarily disable your AVG Internet Security program and check on your issue.
Let us know if you need further assistance.