The only program I know that gives such a message is the Firefox browser or its cousin Thunderbird. It could be Internet Explorer does it also, but I hardly use that. I've never seen it coming from Vista itself.
So pleaste tell more about that.
And then the slowness. Go into task manager and tell the top-5 processes in terms of CPU usage (sort on that column) and how much they use. A common cause (but not the only one) is one program having an excessive use of the CPU.
My computer is very slow. What is a "long running script" and how do I stop it. I get a message on the bottom of the screen that has a stop icon but it doesn't work.