there is no such thing as a totally secure system. i spent many yrs doing "secure" military systems. that animal didn't exist when i became disabled in 91. the security of a system is a function of the value of that is in that system. would you spend $1 million to secure a system that, if compromised,, would only be worth $1.00? no. the cost of security is always less than the vaule of the system.
once upon a time, long ago and far away, i worked with another guy and we were pain to penetrate the secure systems at the pentagon. i can't tell you the results of our probing activities, but we had some geneal officers scratching thei heads.
the only way to make a computer totally safe is to place it in a locked room, unplugged from telephone and electricity, inside a faraday cage. even then i couldn't tell you that was totally secure.
all that said, if you use your home computer, in the privacy of your own home, and access hw, WHO CARES? it's your homw and your computer. a business would be in violation of seveal laws if it pried into your files and history. if at work, that's another story. your employer (several recent court decisions) owns the computer and it's contents. accessing hw from work could get you fired because you are using the computer for non-work related purposes.
hope this helps.