Download the Adobe Flash Player installer directly by right clicking the following links and selecting "Save target as" (IE) or "Save Link as"(Firefox).
Save the files to your Downloads folder - DO NOT run anything yet.
Reboot your system.
BEFORE opening anything, go to the Downloads folder and run the UNINSTALLER to remove all instances of Flash Player.
Next, run the ActiveX installer, and then the (other browsers) Installer.
Note: you WILL NOT find Flash Player in your program files or Start menu, because it ISN'T a program, but a plugin for your browser.
If you want to verify instalation, look in: C/Windows/System32/Macromed and C/Windows/SysWOW64/Macromed
You'll see a Flash folder in each if it's installed.