Nothing happens when I click Itunes

Hello, I am having a problem using itunes. I have downloaded and installed twice. After the first time, it didnt work, so i uninstalled it. Then reinstalled it. This did nothing. When I click on it, I get no error message or anything!

I clicked on Quicktime to see if that works and it works just fine.

I have norton Antivirus, and I have disabled it. I also have the windows firewall and norton firewall, both of which are disabled. I have itunes on my home computer, and it works just fine. I am hoping that someone can help me out so that I can figure it out for this computer.

Thank you. Also, I am running Windows XP home edition, and it is completely up to date with all service packs and updates. Thank you!