Packages Norton Anti Virus Mcafee Anti Virus Choice is simple toss a coin and choose. But I recommend that you should use both because in these times of internet where virus spread like a boooom you should not trust on any one package and use both for more safety. Well as old saying goes 'prevention is better than cure'. Keep your windows operating system CD always ready and in safe place. I can't even see the directory listing.
Solutions Keep it cool.
Take it easy. Have a mug of coffee, sit, relax and start the work. First check for any loose cable or loose card inside your computer. Make sure all cable connections are tight, all the connectors are screwed down and fixed properly in. Check whether your cmos info is all correct.