horizon is not opening when im connected to online ( it flashes the logo then closes ) but opens when im offline i have reinstalled i also have 3.5 and 4.0 .NET’s and i run as admin nothing works please helpppp…
You have something blocking it when it tries to contact the servers. Generally it is an AV or firewall.
i have disabled all of that and ran it still not opening 
There really isn’t much else I can suggest since I’ve never encountered the issue. It is up to you to find what is killing the task when Horizon attempts to connect to the servers. If you are using AVG make sure you are disabling the hot spot shield. Unless you are Diamond or plan on going Diamond you don’t lose any functionality by running in offline mode.
i am going diamond but i didnt want to spend my money and then this happens
but thank you i guess