Frustrated and Ready to Scream!

[CatStarESP4]

I recently came home from Florida and my mom asked me to run a virus scan on our computer. We found three viruses on the system. Two of them were easily deleted, but the third one couldn't. I ran the scan at least two more times to see if it would finally be deleted. No luck! I tried to contact our antivirus provider, but they charge for advice. I tried to get help from their website, but I didn't get the answers I wanted. I am getting frustrated and I on the verge of screaming. Does any have any advise on getting rid of this cyber pest? Advice is appreciated!