.cre file problem

I don't know where to post this so i hope this is right. My computer for some reason started associating cre files with notepad. I went into the registry and deleted the notepad line from "open with" rebooted and still not working. I did a system restore to before it happened, nothing. I uninstalled BG2 deleted the folder and reinstalled and still nothing. I'm hoping someone here can tell me how to fix it.