Renewed AVG Internet Security but it won't install

Just renewed my AVG Internet Security after it expired, download completes but when i try to install i get an error message saying that the download is not compatible with other AVG products on my computer??

Used AVG for years never had an issue, PC running Windows Vista, has Zen and PC Tune Up installed too.

Any ideas, find it impossible to navigate the AVG help and support, it just routes me to a US website

Hello Gary.
I request you to uninstall the currently installed 2015 version and then install the latest 2016 version from the official website and then you will be able to fix this issue.
Thank you.