You need to be logged into an administrator account to install LW. You also should right-click the installer & choose Run as Administrator. An alternative: Try this version: Download ‘Other’ version & simply unzip & use!, but you need to have Java 1.6 installed on your system first: Java Downloads for All Operating Systems - Sun Microsystems & choose the offline 15 MB version. Oh .. and for Vista, right-click the the LW program & choose Run as Admin first.