Hello Vinne,
Thank you for contacting AVG Community Support.
We are glad to clarify this for you.
Yes, you can. Please follow the below link to uninstall the older version and reinstall the latest version of AVG Antivirus.
- Uninstalling: https://support.avg.com/SupportArticleView?urlname=uninstall-avg-antivirus
- Reinstalling https://support.avg.com/SupportArticleView?urlname=install-avg-antivirus-free
Thank you.