Steam doesn't Start

I use Steampowered.
Since a few Weeks, it starts, connects to Steampowered and closes.
I reinstalled it, but it doesn't help.
Problems started when I moved a Download to Top.
Any idea?

Try switching off the computer's Router, and then starting the Steam Client in Offline mode.

I found other suggestions under discussion here: Steam starts up then instantly closes :: Help and Tips

iko22 said:

Try switching off the computer's Router, and then starting the Steam Client in Offline mode.

I found other suggestions under discussion here: Steam starts up then instantly closes :: Help and Tips

My younger brother has been good at school so I installed Steam on the PC so he can play. We were installing the brake kit and atv accessories on the TRX when he mentioned Steam sometimes crash and closes randomly on start. Hope the offline mode would work.

A program that spied the networktraffic where not complete uninstalled and disturbed the networktraffic.
Whithout it all works fine