when I click on the "start backup" button the hourglass start to run but after a while it stops by itself and nothing happens.
it is taking too long, your browser is timing out. Do individual domains or use the automated backup
What can I do to make a manual server backup?
one domain at a time, server configs by them self, etc.
And how to make scheduled backup without another server, other disk nor windows machine?
What are you backing up to? Your system crashes with your backup on it? Makes restores very much trickier. Kind of like Monty Python, bring out your dead.
Jale