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Which windows are you using ?
Please restart your computer and then try fagain to install Adobe Flash Player.
Download the following files by right clicking and selecting "Save target as"
Save ALL files to your Downloads folder - DO NOT RUN anything yet.
Reboot your system.
BEFORE opening anything else, go to your Downloads folder and run the UNINSTALLER to remove all instances of Flash Player.
Next, run the ActiveX Installer.
Lastly, run the Installer for other browsers.
Once everything is installed, see:Enabling Flash Player in Internet Explorer and: ActiveX Filtering in Internet Explorer to make 100% sure that Flash Player is enabled and NOT being blocked by ActiveX controls.