Adobe Flash Player user account controls

Good day!

I am looking for help in Adobe Flash Player.

My computer is in use for two months now and I did not face any problem with Flash Player during that period.  Another application is asking to turn off user account control. After one week  flash stopped. I have uninstalled earlier versions and installed the latest version.

I am not able to use Yahoo messenger and AIM because of the flash problem. The important thing is I am not getting any error messages. My browser is Mozilla Firefox and Operating System is Vista. I am following ‘Install Missing Plug-ins’ > ‘Manual Install’ and it brings to https://get.adobe.com/flashplayer/ and I selected Vista as OS and Firefox as browser and also clicked ‘Agree and Install.’

A pop up is telling ‘Opening install_flash_player.exe’ that is a binary file from http://fpdownload.macromedia.com’. Do you want to save the file?’ with two options. Save File and cancel. I selected Save File. When I finished the download, it says ‘Download Complete’. But when I am going back to the same place where I have downloaded it, nothing is happening. It tells me that  I am missing the ‘additional plug-ins required to show all media on this page.’

I have also turned on the user account control, but there was no change in the result. Please help me somebody to solve this problem. 

Thanks in advance.