Installed Windows 7 and unfortunately zend studio 5.5 won’t start. Here is a quick fix from xlim5 that worked for me:

1. After install Zend studio, right click to shortcut and choose:
2. Troubleshoot compatibility > troubleshoot program > The program worked in earlier versions of Windows but won’t install or run now.
3. Click next and choose “Window Vista” and click Next.

Now Zend can run normally.