Spyware Attacks ........?

This always happens and it pisses me off. All I have is a Free Version of AVG 9.0 or something. But than suddenly a Virus program not even used by your computer come You have 383 Trojans!!! Than its like buy the full version now to Remove threats and it like completely takes over your computer and you try to open the internet and its like Internet Explorer is infected!!! continue unprotected? than you click that and alls it does is keep bringing you back WTF right now some Win 7 spyware crap is doing it to me!