Downloading Flash Player 10 into Mozilla Firefox 3?

[ThriceLabs]

I am using Vista and cannot download Adobe Flash Player 10. I need to use it with Mozilla Firefox 3. I have read the download instructions at get.adobe.com. The download doesn't start automatically, so I click the provided link, as instructed. Apparently, I am supposed to be given the option to "run" or "save" and then click "run." However, I am only given the option to "save" or "cancel." I choose "save." Then, another box opens up and I click on "install_flash_player.exe" I then get a message that this is an executable file which may contain viruses. I choose "ok" and "continue." Finally, I get a message saying that Firefox must be closed before Adobe Flash Player plugin can be installed. I close Firefox and all other programs, yet this message continues to be displayed.

I have Flash Player on my IE 7 browser, but need Firefox for work. Any suggestions will be greatly appreciated.