Download and save the installer to use over again.
Adobe does not make it easy for the average user to acquire the stand-alone full installers and even when you do manage to navigate to their 'Alternative' download page where it looks like you can get the complete installer, all you get is a small file that will initiate the online install, which as it turns out has an even worse sting in the tale. Unless you are observant enough to notice the crapware included by default (fig:1) and uncheck the appropriate tick box you can end up with an unwanted toolbar or virus scanner, or worse still an obnoxious piece of scareware.
Two Versions of Flash for Windows.
Another more direct way to check which version or versions you have installed is to open the Flash Player Settings Manager, which in Windows you will find in the Control Panel. On the Advanced Tab the currently installed update numbers for both the ActiveX and the Plug-in versions will be displayed (fig:4). If you don't have Flash installed or you have a version that is older than 10.3 then you won't have a Control Panel applet.
Yet another way to determine the currently installed Flash version is to look at the list of installed plug-ins or add-ons in a browser. Here are screenshots of where to find this information in Internet Explorer, Firefox and Opera