2 years ago I gave a girl a netbook. The brand was asus ee pc and it was equipped with intel atom. It was kinda sluggish and slow but she said she likes it because it's light and convenient to carry around. Several days ago, the netbook is having problem. I was out of city at the time but according to her, the system became slow so she started up avast. One virus is found and avast tried to remove it but restart is required. But after waiting for few minutes the netbook stalled. It did not shut down. So she hold down the power up to turn of the netbook. When she tried to turn it on, only black screen appeared. She brought it to a local computer shop then they tried to remove the batter then installed it again, finally the netbook can be turned on properly. The technician adviced her to wait a day until a full diagnosis can be given. The next day they told her that they found the virus and the motherboard is having an issue but unfortunately it cannot be repaired.
I truly need help on how to make that laptop securely protected from viruses and any other issue. She likes to watch drama from mysoju.com and I think she got the virus from the pop-ups there. Even Avast couldn't protect her netbook from it. I told her she might pressed a button that allows the virus to get installed.
I'm thinking in combining Microsoft Security Essential + Avast + Malwarebytes(retail version). I read somewhere that having two or more firewalls could cause problems. Can someone clarify that for me? I'm also going to install adblock plus + no script for mozilla firefox. Is there anything else to add? I don't want this laptop to break within 2 years