I wanted to change my game to 1920x1080 resolution. This is but only if I previously the resolution 1280x960 select them. This resolution I did not possess

The game cannot do 1920x1080 by default, it only supports 4:3 resolutions (800x600, 1024x768, 1280x1024, etc.). The resolutions the game makes available to you are restricted by your hardware, so if you have a monitor that cannot do 1280x960, the game will not give you that as an option. In order to get widescreen resolutions, you will need to mod the game:
http://www.wsgf.org/article/star-wars-knights-old-republic

I have only 1024x768. I use the program but in option is only 1024x768

That is covered in the article I linked to. If the option does not appear after you have used the widescreen patcher, you will need to manually edit the swkotor.ini file.

I think that if the article was written in German, then it would be of more use to him.

yes in german is better. i have make that was writt in the article but the game run only witch 1024x768