Do you know why computer systems so vulnerable?
Unfortunately, social networking, websites, and all the virtual which using computer is still vulnerabilities. Some of them have infected zombie computers which can be extremely careful of what information on post of their pages.
All computer users should be very careful when clicking on any link in an email, and if they do decide to click on a link, it source should be one that they can trust. You have to check their website is clear and got security. When you got some JUNK/SPAM email, you should unregistered directly or it might harm your computer.
All the application called ANTI VIRUS is not recommended 100% of erase the virus from your computer, so very careful when you see something different with your computer.
You can’t using the computer like you use the text book or writing on book, only you can write or read. When computer link to the internet, you might meet some of virus and for you which don’t know the IT, you have to learn more about computer before you got very stuck.