When I open WPI, it tells me that there is a new version available and gives me the option to download or decline. If I choose "I Decline" WPI4 opens as normal, but if click "I Accept" to download the new version, it begins the installation process, but
after a few seconds it rollsback with a message "Failed to install Web Platform Installer. Click OK to use the browser to download installer." But when i download the file, it too, fails to install. I begin the installation (of WPI4.5), but it soon rollsback
with a message "Microsoft Web Platform Installer 4.5 Setup Wizard ended prematurely." Please help me get WPI upgraded to 4.5 
I looked for the installation log file at %temp%\webpi_launcher.txt, but that file doesn't exist