why cant i open my itunes on the desk top i downloaded it yesterday?

Do you get an error message when you try to launch iTunes? If so, what does it say? (Precise text, please.)

I'm having the same problem. Already followed the steps and removed the SC info.sibd file then repaired the Quicktime program. Nothing has worked. Should I remove the Itunes program? I recently updated Iphone and synced iphone and ipod now cant open itunes at all. No error message. The icon thinks a moment then does not open.