A driver is a special type of software. Whenever your PC needs to connect toand control a peripheral device like a printer or scanner the driver written towork with it is required.
The level of the driver needs to be matched to the level of the device it iscontrolling. Some drivers are backward compatible. HP has done a good job withits PCL (printer control language) by making each successive PCL versionbackward compatible with earlier versions of printers. This can save a lot ofheadaches for you.
If you lose a driver or have the wrong one installed your peripheral devicebecomes a 10 pound paper weight.
So what do you do if you need a driver? Try going to the hardware manufactureswebsite and looking for a link to drivers. You may have to click around a lotto get to the right spot depending on teh organization of the web pages. Onceyou do you'll need to enter the model of the hardware you seeking the driverfor. Then you can download and install it following the instructionm that comewith it.