n install of P3D V2.5. When executing an installer exe and upon clicking "run" on the warning dialog nothing happens. I have tried running as administrator and without the virus scanner with no success.
This doesn't have anything to do with the sim used, since the installer hasn't even got a chance to start, according to your report, so I changed the subject thread to something more appropriate.
Something in your computer is blocking the installer from running, and the most common case it's the antivirus, so you must disable it. Another possible reason is that you have inadvertently put us in the untrusted publishers:
To fix this, you can go to the Control Panel, under "Internet Options", look for the "Content" tab, there should be an "Publishers" button, that will list the software authors that you trusted, and another tab with untrusted authors. If you see "Virtuali s.a.s", remove it from both tabs (especially if it's under untrusted)
If this doens't fix it, it's possible that instead, you simply started the installer a 2nd time because it didn't seemed to work the first time (it was probably working, and you simply had to wait a bit), so the 2nd click caused the fist installer to be stuck.
To fix this, restart Windows and try again, and wait for the installer to start without trying to click again on it. If your antivirus is still active, it will take a while for the installer to start, because the antivirus is slowing it down by examining all files, one by one, while they are uncompressed in the Windows temporary folder.
