It's relatively easy to find device drivers of branded Wintel machines: usually you can visit the vendor's site and get a list of drivers for your model. However, it's not always that easy because the same model may come up with with different graphics cards, for example. More importantly, you never know when a newer version of one of your device drivers comes out.
Wait no more, Driver Max is here. This highly acclaimed freeware tool for Windows can extract all your installed drivers for you to take a backup. It can also tell you which of your drivers should be updated by connecting to the Driver Max website. The only downside right now is that the website doesn't give you links to download those updated drivers.
Just for the sake of completion, Driver Detective is a similar (and perhaps, more complete program). It's not freeware, though.