thank you for your answers!
i have tried running s&m3 with antivirus software and skype im client deactivated, that didn't change a thing.
in 1 and 2 i could at least reach the options once and turned the quality setting to low. but in 3 that does not work anymore.
when pressing options, i hear the sound, event the word 'options' gets a little bit bigger and the red triangle moves to options but that's it. and when i press ESC the options screen opens but closes a quarter of a second later. i can see that the quality is set to high though, but change nothing.
i know that the laptop and the graphics card are not very new, but as i said half life 2 was running smooth on that machine in fullscreen at a higher resolution.
but i can still live with the slow graphics if the sound is not distorted and stuttering and repeating. i have already set all driver settings i found to more performance and less quality with no noticable effect.
trying to switch to fullscreen with alt+enter crashed the game 'access violation, trying to write to ... terminating program' (or something like that.
but i can even accept running the game in this one and only resolution in a window with a slow framerate, if i could only reach options....

by the way, if i start the game and press load/save i can load the last saved game. but if i press options (and the above happens) none of the buttons works anymore, load/save included. so the game has to be started again. only the button sound and the word getting bigger happens.
i have made a dxdiag-file and attached it as a zip-file.
sorry if my english is a bit bumpy here or there....