User-Agent: Mozilla/5.0 (Windows; U; Windows NT 5.1; en-US; rv:1.8.0.1) Gecko/20060111 Firefox/1.5.0.1 Build Identifier: Mozilla/5.0 (Windows; U; Windows NT 5.1; en-US; rv:1.8.0.1) Gecko/20060111 Firefox/1.5.0.1 I store my Firefox profile on a removable drive. If I attempt to open Firefox without the drive plugged in, it returns the error message "Firefox is already running, but is not responding. To open a new window, you must first close the existing Firefox process, or restart your system." Firefox is assuming incorrectly that since it cannot locate the default profile, the profile must already be in use. This has occurred for several past releases of Firefox, with some rewording of the error message. Reproducible: Always Steps to Reproduce: 1. Create default profile on removeable media 2. Remove the media which contains the profile 3. Attempt to open Firefox Actual Results: Firefox returned the given error and did not open. Expected Results: Firefox should return a more specific error message stating that the default profile can not be located.

*** This bug has been marked as a duplicate of 278860 ***