Well you can set windows to automaticly download and install updates for you....thats of course if your running windows?....the same can be done in Linux and OSX.
However drivers on the other hand,you will need to keep checking for updates manualy,i have heard of some software that you can buy that actualy scans what you have on your pc and searches for all updates but ive never trusted one.
Some software such as Adobe,Creative,Itunes have this built in and they search themselves for the latest version and ask you if you want to install them....same goes with antivirus software.