First off, I must say I am a complete novice and have no idea what I am doing.

I recently purchased PhotoPost and was attempting to install, but never got past the initial attempt. I followed the directions (set up a database on my server) and then tried to open "install.php" in my browser (using the full path...starting with C:/documents and settings/etc), and it brought up a box that asked if I wanted to save or run. I said save, and it did, and then it asked if I wanted to open. I said yes, after which it tried to open the program with Picture It Publishing and then said the file could not be opened. I am sore confused. What do I do now?