I've been reading some of the posts here about TCP Optimizer. I'd really like to give this a try, but as I don't want to cock up my system, which I've managed to do quite easily before

, I'd like to know is it really safe and easy to use? Does it really make a noticeable difference?
The last thing I want to do is create a problem by changing things I don't understand. At the moment my system is running OK, but I don't actually know enough about the tech side to say whether it is properly optimised for broadband.
I'm on VM 4Mb cable.