Recently, one of my clients let their subscription to AVG anti-virus lapse and all 8 computers on their network were complaining about the subscription having expired. I purchased a new license key and went about putting it into the AVG's that were running. Strangely, the field for the license number was grayed out so I couldn't paste it in.
They are set up with the AVG admin console so I thought maybe that was the way to go. There is a very clear sequence of steps outlined on a number of web sites. I thought this was the clearest. I followed that procedure. No luck.
It turns out that if your license expires more than 15 days previously, AVG clients shut down and don't want to do much of anything.
A quick call to the very nice folks at AVG came up with a suggestion of deleting the avg.snu file in the programs/avg/2013 folder and then reopening the interface. AVG nicely comes up and asks for the new key but seems a little confused and unable to verify that this is a valid license key. The next step is running the add/remove programs (click start, run and type appwiz.cpl) - right click on AVG when the list populates and select change. Then do a repair install of AVG. The first thing it asks for is the new license key and it seemed happy to take it this time.
ok, rinse and repeat 8 times. What fun. I hope this saves someone some time.