Whenever I run the exe file, I get a remark that I there is "insufficient user privileges to install application". What is the best approach to this problem?
Microsoft embeds Flash Player for IE and Edge browses in Windows 10 and distributes Flash Player via Windows Updates, therefore, I'm assuming you're attempting to install Flash Player for Firefox or Opera. If you were trying to run the EXE installer for the Flash Player for IE installer it would return a different error.
Flash Player requires Admin permissions to install. If you're getting this message it usually means the user you are logged in as does not have Admin permissions to install Flash Player. Please post the FlashInstall.log file saved at C:\Windows\System32\Macromed\Flash. If this is a 64-bit OS there is another FlashInstall.log file saved at C:\Windows\SysWOW64\Macromed\Flash. Both files are required from a 64-bit OS to investigate further. The files may be fairly large, as such, please upload them using the instructions The specified item was not found..
Also, please post a screenshot (see The specified item was not found.) of the installer dialog window with the error message.