I like to think I am pretty handy with computers but I know I could be better. I have recently landed a job where I will be trouble shooting windows systems. This has brought me to realize hey I have no idea how to find a remove viruses without reformatting the computer. Nor do I know how to check a file to see if it was safe or not, even if I opened it in a virtual pc or sandbox.
Currently I have no money, so going to school for a computer science education is not in my near future, but I have access to books and internet resources that I can learn on my own from. So what I need help with is where should I start. Can anyone give some advice of how to go from a user that knows how to download drivers for your video card and replace broken hard drives to someone that can find viruses you never knew you had. What should I learn first so I am not watching youtube lectures that are above my head thus I don't get much from them.