In computer technology, bad drivers are drivers that are poor performing, unreliable, buggy and/or lacking full support of the respective hardware's features.

Bad drivers are the bane of Linux use. This is not a fault of Linux itself, but rather with the hardware companies unwillingness to release their own drivers or provide enough technical information so proper drivers can be written. The most frequent problem with bad drivers under Linux isn't instability or bugs, it's lack of full support of the hardware's features. Most hardcore Linux users will not buy hardware that is known to have bad Linux support.

The problem isn't limited to Linux, Windows has more than its fare share of bad driver problems. This problem is most prevalent in video hardware; with new products being released on faster timetables, many get released with incomplete drivers. It has become generally accepted that the driver disk included with your video card is only good for the bundled software - the drivers on it are already ancient. Many hardware vendors realize this and it perpetuates the problem - they just assume by the time the hardware has been produced, boxed, shipped and sold, they'll have fully tested drivers available on their web site.

Some companies simply cannot produce good drivers at all. When S3 was still a player in the graphics card arena, the cards all suffered from VERY bad drivers. Many popular games had visual glitches or crashed, and to this day there are no GOOD drivers for the Savage4 or Savage2000 based S3 cards.