Do I Have A Virus In My computer?

I need help quick when i started my computer and logged onto the Admin the whole screen is red!and theres no programs runnning and when ever i start a game on other users it says That my sound card isnt in but i dont think i have one but before it worked perfectly and i didnt know anything about a sound card!Im just a 10 year old kid becuz im using my Bros user but anyway plz help me and i need at least 6-12 answers plz help!!!P.S. These are things that my friend downloaded on my Comuter "Ares"And "KGB Archiver.He said its for getting free games on download and i think thats the problem but if you know andything about this plz add me.whoever has the correct answer gets 5 stars.!