Trojan Virus' help!!!!! EMERGENCY I DONT HAVE MUCH TIME!!?

[Vikki2796]

Ever since I let my little cousin go on this website to show me a game (it was crap so i never went back on it), my laptop has managed to get 339 Trojan Virus' and my facebook account is under attack from being taken over. Loads of notifications are popping up syaing TROJAN! ALERT! MALICIOUS SOFTWARE! and things like that and my antivirus has obviously been crap. My antivirus is avast! the free one and has been playing up since Igot the free one because I had the paid one free for a few weeks. My computer is under attack and someones trying to gain my passwords and my whole laptops control help me this is serious its the worst its ever been and more pop-ups are still coming you have to help me someone there has to be something someone could do :'( I'm really scared because my laptop was only fixed a month ago by my uncle and he will be really mad!
My security center isnt starting, internet protection is trying to be found but they want me to pay and whats worse is its in Dollars and Im in england! Please Im begging somebody to help me :'(
Thank You!
WTF - It was my little cousin he came round my house because my aunt wanted me to look after him for a while because she had to go somewhere and I said that it would be fine so he asked if we could go on my laptop and I was only on the games on facebook (just the cab one) and he said its boring and askedif he could show me a game and he found a virus one! So dont say oh yeah sure i bet it was your little cousin you just blame him BECAUSE I WAS!!!!!!!
Thanks for your quick response Ill try the video and then disconnect my laptop if it keeps happening! Argh I am freaking out! But thanks!
Cody - The scan started immediately and my computer is badly under attack in a few seconds it already told me that the damage was high Should I let it scan then restart and do the next steps?
Cody - I still have 259 errors and its asking me to get the PRO :'( Thanks for your help in removing some but is there anything else I can do?

[Harvey Franklin]

If there is nothing you can do disconnect the internet then they can't get acsses!

[ArmyCadetLad]

Really Not much you can do. personally i would close your laptop ( Shut down ) and leave it for a day go on it tomorrow see if its still popping up. if your security on your laptop isnt good you cant expect not to get viruses

[Sly_Old_Mole]

339 Trojan Virus' - not true - fake.

You have malware.

will free malwarebytes run ?

The name of the program its asking you to buy would help, for that is the name of your malware.

Edit:

but is there anything else I can do - YES tell us the name of the program its asking you to buy.

[Cameron]

get a Mac and say good bye to virus's. no need for that norton crap