Cannot install application on Vista

[laurent22300]

Hello,

For some reasons, my installer doesn't work on Windows Vista (french version). When I try to install my app to the default folder (c:\program files\app), I get this error for each file:

code:
Error opening file for writing: <name of file>

On the other hand, if I try to install the app in a folder other than "Program files" then the installation works fine. Does anybody know what could be the problem? I assume it's not the UAC since it would display a message and not just silently block the installation, right? Any ideas?

Thanks,

Laurent