Netbook slow after system restore?

So recently I ran into some viruses that I couldn't remove so I just decided to restore my system to factory settings. It wiped out everything and I started off with a clean slate. I have just finished downloading the must have programs (Flash, Java, Avast Anti-Virus) and I noticed that my netbook is running slower than when it had viruses. Can anyone help?? I'm not very computer savy. Thank you God Bless!!