The maximal path length handling in the Qt windows installer (tested with 4.3.2 OpenSource version) is broken. The Installer limits the installation path length to 400, but the following actions cannot handle that path length. No files are installed and the resulting shortcuts are invalid.

Installer allows 400 characters as installation "Destination folder":
C:\Qt\Trolltech_Code_less_create_more\TrolltechCode_less_create_more\TrolltechCode_less_create_more\TrolltechCode_less_create_more\TrolltechCode_less_create_more\TrolltechCode_less_create_more\TrolltechCode_less_create_more\TrolltechCode_less_create_more\TrolltechCode_less_create_more\TrolltechCode_less_create_more\TrolltechCode_less_create_more\TrolltechCode_less_create___

"Target" in resulting command line shortcut:
C:\WINDOWS\system32\cmd.exe eate_more\Trolltech_Code_less_create_more\TrolltechCode_less_create_more\Trolltech_Code_less_create_more?/k "C

"Start in" in resulting command line shortcut:
C:\Qt\Trolltech_Code_less_create_more\TrolltechCode_less_create_more\TrolltechCode_less_create_more\TrolltechCode_less_create_more\TrolltechCode_less_create_more\TrolltechCode_less_create_more\TrolltechCode_less_create_more\Trolltech_Code_less_c

Maybe an upograde of the used NSIS version would help