I am not familiar with the difference between running Firefox as administrator vs. a different user.

Flash 11.3 and higher is designed to create a sandbox to better isolate bad Flash processes from one another. This involves the creation of numerous separate Windows processes, and it may be that this isn't working correctly with user-level privileges.

You can disable this feature, known as protected mode, by following this support article from Adobe under the heading "Last Resort": Adobe Forums: How do I troubleshoot Flash Player's protected mode for Firefox?

If you find you are still having problems with Flash 11.3 and higher, this is some standard guidance that addresses the most common issues. I'm sure you've seen some of it before, but just in case:

(1) If you have installed any recorders/downloaders that interact with Flash media, make sure they are as up-to-date as possible, or disable them temporarily.

(2) Disable hardware graphics acceleration in Firefox and in Flash

(A) In Firefox, un-check the box here and restart:

orange Firefox button (or Tools menu) > Options > Advanced > General > "Use hardware acceleration when available"

(B) In Flash, see this support article from Adobe: http://helpx.adobe.com/flash-player/kb/video-playback-issues.html#main_Solve_video_playback_issues

Can you not just download the Flash plugin installer, then quit Firefox and install it from there? That is the way I used to do it when I was using Windows, and the way I still do it with Mac OS. The page where you get them is here:

• http://www.adobe.com/products/flashplayer/distribution3.html

I disabled the HW acceleration, which didn't solve the problem. The way I installed the Flash software, was to download it from their site. The link I used was http://get.adobe.com/reader/ , The file is called, install_reader11_en_mssd_aaa_aih.exe. I installed it from my explorer. I did exit the Firefox executable, first. I also tried the link, http://helpx.adobe.com/flash-player/kb/video-playback-issues.html#main_Solve_video_playback_issues . It wasn't very helpful, because, it's loading flash player and hung the Firefox executable. I still need to investigate their suggested solutions, further.

I tried everything that you recommended, except the adobe help pages. The adobe help pages hang my Firefox. Each page loads the flash player, hangs the executable, then produces no output. Even the settings page doesn't load, it hangs, then remains blank. I can't adjust the settings, if I can't see them.

I downloaded a debug version of 10.3, which has been updated. http://download.macromedia.com/pub/flashplayer/installers/archive/fp_10.3.183.67_archive.zip

Hi immenotyou, is the problem solved with 10.3 or are you saying you can't keep 10.3 because it keeps updating to 11.8?

I updated it myself, not automatically. My only point is that ever since protected mode was introduced, I haven't been able to install the new version of Flash Player. Flash Player was working, until I installed the new version, with protected mode. It should work when installed. There have been several updates to Flash Player, yet none have fixed the problem. Diagnosing the problem is nearly impossible, since it requires me to install a Flash Player that hangs and produces no output when it stops hanging, except for a popup from Firefox asking me, if I want to stop an unresponsive script. So I uninstalled Flash Player and installed the 10.3 version. It's fine for now with the 10.3 version. When I do the next update to Firefox and the plugins, I don't want to have the older version of Flash Player be disabled and be prompted to activate it each time. I thought it would be best if I tried to solve the problem.