Bypass the "downloader/installer" altogether.
Download the Adobe Flash Player Uninstaller and FULL installer(s) directly by right clicking the following links and selecting "Save target as" (IE) or "Save Link as" (Firefox).
Save the file(s) to your downloads folder - DO NOT RUN anything yet.
Reboot your system.
BEFORE opening anything, go to your Downloads folder and run the UNINSTALLER and then the installer(s).