The last couple of days whilst on-line I've had a interruption saying a threat has been detected by this Windows AVG page and it comes up saying 9 threats found on Hard Drive and when I exit it asks whether I want to download it to remove the threats. Is this as I think, some site trying to get me to download and purchase a security package. Being a wrinklie this sort of action, I find confusing and I already have a Security system unstalled. Thanks for any advice.
never download anything from the Internet that you are unsure of.
If I was you I would do a full Scan with your Anti-Virus product just in case you have a bogey on your PC.
I use Microsoft Security Essentials to protect my PC.
Have you got Malwarebytes installed so you can do a scan with that if need be.