trouble downloading Flash

I tried to download the latest Adobe Flash Player on my Mac OS X, with Safari (the latest update). I got to the end, and it said it had been installed, and "Please restart all open browsers to complete the installation." Well, there weren't any open browsers as I'd closed Safari per its instructions. I tried opening Safari and going back to what I'd been doing (Weight Watchers.com which now requires Flash to display) and no Flash. I installed all over again and tried restarting the computer. No Flash. What am I doing wrong? Thanks!

As far as I know, Flash Player is downloaded in a .dmg (disk image) file. This must be double-clicked to mount on the desktop, then the installer inside is run. Is this what you did?