Thankyou to everyone who responded to my problem. I got this back from the support team:

“The number is valid. Use copy & paste method to enter it into avast!
and keep on mind that this number can´t be used on any server
operating system. Also you have to be logged to Windows with
administrators rights and the date/year indicated on your computer
must be correct.”

Im using Windows ME. Administrators rights?, server opertaing system? What on Earth is that, never heard of it before. And my system clock is correct. As you can tell im not much of a computer expert. lol Avast also screwed up all my server setting in email and I couldnt send any email .

I’ve re-installed AVG antivirus for now. Might give avast another try some other time.