Check your GPU (as well as sound) drivers, and update to the latest version if necessary. After that, try the games again and if they still crash, it might be because of an update (or you just didn't install it properly... somehow).
So guys, recently I noticed my TF2 crashing a lot. It runs fine and then suddenly it decides to say "hl2.exe has stopped responding", and it does the usual not responding **** and dies. I'm not sure whether this is because of the recent update, but it's been running perfectly fine for weeks, even yesterday. This may be unrelated, but Minecraft crashes frequently as well, but this has been going on a while. I'm not jumping to conclusions yet, but I think it might be some error with my computer. I'll give it a few more days and see if the problem persists. What do you guys think?
Check your GPU (as well as sound) drivers, and update to the latest version if necessary. After that, try the games again and if they still crash, it might be because of an update (or you just didn't install it properly... somehow).
「僕たちの前にはいまだ巨大すぎる人生が、茫漠とした時間がどうしようもなく横たわっていた。 」
"We live in a very special time: the only time where we can observationally verify that we live at a very special time." -Lawrence Krauss
Use steam to verify the integrity of your game files. Go to your game, right click on it and go to properties. In the local files tab of the properties window you will find a button that will let you verify the integrity of the game cache. If that fails, uninstall and reinstall. Get back to me with the results from those methods.
Does it crash with an error or does it just go poof? If it just goes poof go to computer->right-click->manage->event viewer->windows logs->application immediately after the program fails and see if it's got an event logged there as an error and if it'll give you more information. If not then you probably just dced or something and the application closed itself without raising an error.