System Sound

[Şerban S.]

I was quite specific about what file format and specs to use. If you're going to use someone else's instructions, then you'll have to ask that guy for his help. Cheers

That's too harsh!

[...]  So I would like to change logout sound to something [...]

You asked too much from Jerry. He already does much more than we'll ever grasp.
What you need to do:
Learn audio editing. There is a lot of stuff to learn. Jerry pointed you to the right direction but it looks you never did sound editing so that is why it sounded weird to you.
The program you need to do various tasks, such as creating system sounds out of various tracks, is called Audacity.
Search and study articles about audio editing. There is a lot of stuff to learn, so go ahead and start learning and practicing with Audacity.
Good luck!