All this info is probably available around the forum, I just though it could be really useful specially for newbies. I tried setting proxies on imacros, but due to continuous Firefox crashes I decided to use this method instead. If this is not the right forum, please OP move as desired. By setting diferent Firefox profiles you can isolate the risk of being banned or having software crashes, well, at least you can isolate those crashes. First of all, the big Q -----------> Do I need proxied for using different Firefox instances? Yep, you always better need proxies.Otherwise you would be just wasting your time setting useless profiles with the same IP. Windows HowTo Right click on your Firefox shortcut, go to properties, in target option you will see something like "C:\Program Files\Mozilla Firefox\firefox.exe", it may differ depending on your Windows system. Add the following characters: -P –no-remote Now you get: "C:\Program Files\Mozilla Firefox\firefox.exe" -P –no-remote Every time you start Firefox with this shortcut it will prompt you to choose a profile. You can also set the default profile from this first prompt, but better be asked every time for your profile. In case you want to set some default “serious profile” (for instance, local ip, no proxy at all, regular home use) it is better creating another shortcut with the following "C:\Program Files\Mozilla Firefox\firefox.exe" -P "My Profile" -no-remote OSx HowTo Ok, here we don´t have the nice shortcut option, so we will have to build a small Apple script using Automator. Many Apple users may have never used such tool, but it is amazing, if you are an OSx user and you have the time you should research into it. Open Automator Whem prompted for a template click on application. From the large utilities scripts, choose Run Shell Script. Paste the following: /Applications/Firefox.app/Contents/MacOS/firefox-bin –ProfileManager Now go to Choose File / Save As an application. In order to have another shortcut for launching a certain profile, you can make another automation with the following script: /Applications/Firefox.app/Contents/MacOS/firefox-bin -P MyProfile How to organize a large bunch of profiles? This all depends on you, we all wipe one´s bottom in a different way. I usually install the following Firefox addons: Profile Switcher: you get a name / profile icon in the status bar, easy when you don´t trust on your clicking at 5am. Your IP: Better be sure, you have your IP stated in the status bar. In case you don´t go to bed that early, better double check ;-) Any memory usage / memory restart addon iMacros: This one is really useful, many recipes in there. FEBE: This is a personal choice, it is useful for backing up / restoring profiles. I usually synch everything on dropbox, so I can have all my profiles in different computers with the same resources. Last but not least, you have to set your proxies in every Firefox instance. Once you do this in one computer you may transfer those details backing up / restoring. Hope anyone finds the above method useful. There are many different ways to accomplish the same thing, I am just detailing what I prefer the most for my daily use.