AVG tech Pay us $125 and your computer will work better then before Internet

Downloaded AVG free anti virus program. I already had paid for it on my PC - funny it has sort of the same problem. Hmmmm! Right after it was done it ask to keep working or shutdown restart now. I did shut down/restart. In restart Dell startup could be seen, but then it went dark. After two days of trying to get help lady asking questions- says basically it's my fault I must have had a popup. They can have a tech guy help me. I ask how much "well to start with Dx $125, but he will have your computer running better then before!" my computer was fine until I down loaded your program & now I'm wondering if the paid version did something to my other PC.