Make sure that the licence file, psrX.lic, is not write-protected or hidden. In addition, in Windows Vista and more recent versions (Windows7), the licence file must not be saved directly to the All Programs folder.
We recommend that the licence file is saved to My Documents (XP) or Documents (Vista/Windows7/Windows8) on a single workstation version.
The licence file must be saved to a network share in a multiuser installation. Check that all users have write access to the licence file.