The configuration of my OS went bad. AVG vanished from computer. Some corruption of registry keys was the problem. I contacted AVG technical support and then he referred me to an expert. The expert called me on phone and said it will be fixed by remote access but I have to pay 200 dollar fee. I told him that i will simply re-install the OS. He said that there is no way I can fix this on my own and it definitely requires remote access and that they will do PC tuneup and clean all the registry, even repair the OS and they have special tools which are not for public. Then he persuaded me to pay the $200 fee and told me to get my credit card ready and that an automated machine will take my information. I said i'll try on my own but he kept insisting to pay $200 or else the entire computer will get damaged due to infection. I hung up the phone. He called 2 times and I didn't pick up. Then I simply re-installed the entire operating system and the problem was solved. It was that simple.