Hello, x2495iiii.
Thank you very much for your advice.
As for my response (to your suggestions), going in order from what you listed...;
I will try re-installing; I hadn't thought of that. Thanks!

My worlds aren't usually very large. It's about halfway into the world (when I'm done adding all the objects, and all meaning the very few I use), and have started working on the actions that they do, does it crash. Usually it crashes after I click Play, to preview my work thus far.
I haven't imported any sounds yet, having not needed too.
My computer (a Toshiba Windows Vista Premium laptop) is fairly new, and is very compatible. Up until a few days after I got the Alice program downloaded, it was running fine when Alice was up, but now Alice keeps shutting down on me. Also, I don't usually have other windows up when I'm running Alice.
Thank you for your advice!