http://forums.comodo.com/defense-sandbox-help-cis/defense-in-clean-pc-mode-is-blocking-flash-uploader-in-firefox-3612-t64628.0.html;msg459022#msg459022

   1) Open Comodo Firewall (right-click the Comodo tray icon and select Open)

   2) Select Tasks -> Sandbox Tasks -> Open Advanced Settings

   3) In the "Advanced Settings" Window, select Defense+ -> HIPS -> Hips Rules

   4) Find the entry for Firefox.exe. Right-Click it and Select Edit.

   5) In the Comodo HIPS Rule for Firefox.exe window, select the "Access Rights" tab. Locate the "Run an executable" option. Click the modify link under the "Exclusions" column.

   6) In the "Run an Executable" window, select the "Blocked Files/Folder" tab.  Select the plugincontainer.exe entry and right-click -> remove to delete it. Do the same for the crashreporter.exe entry.

   7) Click "OK" on each of the Comodo Firewall widows to save the changes and close the window.

On a brand new machine, I added my desired desired programs. These included Comodo Firewall and Firefox with assorted plugins and addons (including Adobe Flash Player, NoScript, FlashBlock, AdBlock Plus). I soon discovered that videos would not play (Initially I could see some videos if they were using HTML5, but after some tweaks they were gone too). I tried MANY suggestions and tweaks found on various boards, nothing worked. I should have learned long ago that I need to document ALL CHANGES I make to my system - but old habits die hard. I tried many things, with no notes written. I didn't know what issue was preventing Firefox from playing videos. Nothing I tried worked. After no success, I reset Firefox (sad to see my custom settings go). When I restarted Firefox with only the Flash Player plugin active, I still couldn't play videos. More searches followed. I finally stumbled upon the solution on the Comodo site: http://forums.comodo.com/defense-sandbox-help-cis/defense-in-clean-pc-mode-is-blocking-flash-uploader-in-firefox-3612-t64628.0.html;msg459022#msg459022 There I learned that Comodo Defense+ had blocked the Firefox Plugin Container (and Crash Reporter) from running. I used the following steps to fix the problem on my system (w/Comodo Firewall 7.0.317799.4142): 1) Open Comodo Firewall (right-click the Comodo tray icon and select Open) 2) Select Tasks -> Sandbox Tasks -> Open Advanced Settings 3) In the "Advanced Settings" Window, select Defense+ -> HIPS -> Hips Rules 4) Find the entry for Firefox.exe. Right-Click it and Select Edit. 5) In the Comodo HIPS Rule for Firefox.exe window, select the "Access Rights" tab. Locate the "Run an executable" option. Click the modify link under the "Exclusions" column. 6) In the "Run an Executable" window, select the "Blocked Files/Folder" tab. Select the plugincontainer.exe entry and right-click -> remove to delete it. Do the same for the crashreporter.exe entry. 7) Click "OK" on each of the Comodo Firewall widows to save the changes and close the window. After I did this, videos would play. My next task will be to reinstall my favorite extensions and see if I can get Firefox to work as I liked it on my old PC. I hope this helps anyone with a similar setup.