First try disabling your firewall / anti-virus that could be blocking it.
Also make sure your have the latest version of .NetFrameWork. (3.5 or 4 is fine)
Download that here: http://www.microsoft.com/en-us/downl....aspx?id=17851
Also, when you downloaded Horizon did you fully finish the download?
It may be corrupted. unlikely, but try it.
Originally Posted by oat12
Same here its not starting up for me : (
What message are you receiving?