for some reason when I reinstalled KOTOR today it doesn't work.just plays the LA and Bioware logo than crashes,what should I do?what's bizarre is that it worked the first time I installed it.

Where did you buy it? E.g. retail or Steam version?

This is KOTOR 1 right? 2 did that and I never did get it to run.
Here is one link on how to fix a certain crash.
http://www.rossheintzkill.com/knights-of-the-old-republic-crash-to-desktop-glitch/

There is also an alternate SWKOTOR1 exe file out there that you can download (google it) and should fix a lot of other problems. Also, did you change or update your virus protection since the last time when it actually worked? AVG needs to be totally shut off for any LucasArts game or it's no go.

My guess would be drivers. nVidia right? It's always nVidia...

That's how it always was for me. If I tried it some ten times in a row eventually it would work for some reason.

But later I found an easier way was to start the game on windowed mode, that way it wouldn't crash, even if I turned it into fullscreen after I loaded my game. It also crashed during pre-rendered cinematics if it was on fullscreen, for those it was best to save before they came up (traveling between worlds, etc.), watch them on windowed and only change to fullscreen after gameplay resumed.

I think you have to go to the ini file and set it to Fullscreen=0 for it to start on windowed mode. Give it a shot.

Steam

I would check Steam forums for advise but I recall the game has unusual issues with VSync. I always used a fix because that's necessary to run the game with the widescreen hack (I think) but it still crashed and what not.

No problem here, no.

Didn't mean to imply that one or the other has it better/worse, just my general observation. :)

I did have some issues with ATI drivers, but these seem to be more readily fixable for some reason. As always YMMV.

Soooo...Did you get it running?

it still crashes

Have you tried renaming the following files in the movies folder? biologo.bik, leclogo.bik and legal.bik. These files are for the logos that show up when you start the game and they were causing my game to crash.

Here is a link to a thread in the lucasarts forums with additional remedies that work for some people.

http://www.lucasforums.com/showthread.php?t=194296

Precisely why I avoid their shitty cards, man do I have some stories, grr!

What fixes have you tried?

Did you try the "Disable Vertex Buffer Objects=1" fix? How avout the Windowed "Fullscreen=0" fix? That's the one that did it for me.