There are two main problems with running KoTOR on Vista and this article will try to detail each of them. The first and perhaps easiest problem to solve occurs when a graphics card driver is either out-of-date or is read as such by the game’s hardware scan. To fix this problem, it is first advised to remove all graphics drivers currently installed and find the latest drivers download on the internet.

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Once installed, the new drivers should effectively solve the KoTOR on Vista issues, although there may still be concern. Not only can newer nVIDIA drivers be read as not compatible by the game, but even ATI drivers may also encounter the same difficulties, which renders play on Vista impossible without first converting your desktop drivers. A tool to convert those drivers can be found
here, although it may impact performance, it will upgrade functionality with a range of OpenGL issues in games.
Furthermore, the drivers concern would also occur if users are trying to get KoTOR to work on a laptop, inherently containing an integrated graphics chip with generic drivers, thus making this problem impossible to solve. Therefore, it is best advised that KoTOR on Vista should only be handled on a desktop PC, as opposed to laptop interface.