I recently downloaded the game half-life through bittorent, and have installed it, but when I try to open the program, it opens, but then it closes automatically. Am I doing something wrong?

...Yes, it’s called stealing.

Just buy the game, Steam will mess you about that much with an official copy that you wont even consider the pirate copy.

You can buy the game for about £2 now...would've been quicker to actually get it. And yeah, you are doing summat wrong. You need a little program to make it run.