You eather have a virus witch makes every file not work so you cant get rid of it, or you are trying to use applications not supported by windows. if you have a virus that bad the only way to get rid of it is to reinstall windows, or you could try a virus scanner but those never work after you already have a virus. try using a normal program that everyone uses and see if it works, if it does that means you are downloading the wrong kind of apps. and you need to give more information like what type of computer you have and what kind of windows/operating system you are running etc.