AVG problems

I’m having a problem getting avg free to work on my computer. When I restart the computer it tells me that I need to either reload or enter the licence numnber. I can’t enter the licence number because I can’t open AVG. So I click on reinstall. While reinstalling it it gives me an error. Saying that it can’t go any where. I’ve tried to uninstall it and I get the same error message. Is there a program that will remove this software or can anyone give me an idea on how to uninstall?