Was there any solution found to this? I'm having exactly the same problem (Vista Home Premium). Calibre installs, but doesn't create a desktop icon even if that option is selected. When I run Cabire from the start menu, it asks for the folder location of the eBook library, and then goes no futher. "calibre.exe" appears in the 'Processes' list of the Task Manager and is using >50% of the CPU. But no GUI. Stays like this until I end the process in Task Manager.
I've also tried all the suggestions in the FAQs, including running everything as administrator and turning off any antivirus programs. I get the same message as ht1948 from the command line debugger: "link hasn't been detected".