I used to be able to run two separate firefox processes and so also run two separate user profiles at the same time as well. But i recently moved to firefox 4 and windows 7 and one or both of these prevents the old method i used from working. I basically would run firefox (via "run" or through an edited shortcut) with the following executable flags: -p profilename -noremote

And it would launch a separate process running under the profile name. Is there a way to do this with firefox 4 and win7? I am a developer (web and desktop applications) and it is highly preferable to do this. One reason is that if one of the processes crash, the other is fine. Another is to have separate profiles so addons with memory leaks, like firebug, can be run in its own processes and i can restart it when i need to without affecting the other process. I sometimes also need to set the cpu affinity so that one firefox process won't be a hog. Any help would be appreciated.