What version of Firefox are you running?<br> What operating system is you computer using?<br> Does Firefox run at all?<br> When did this problem first occur? Make sure to scan for viruses, malware and bad registries.

firefox.exe "about:blank"

Couple thoughts: (1) Does Firefox still seem to have an active window "somewhere" based on having a tile on the Windows 7 Task Bar? If so, how did you try to maximize it? If you think Firefox is running but is off-screen, check out this post for getting a normally positioned window: https://support.mozilla.org/questions/941896#answer-381295 (2) Does your home page use any Flash media? If so, try disabling the Flash Player plugin's protected mode. See this support article from Adobe under the heading "Last Resort": [http://forums.adobe.com/message/4468493#TemporaryWorkaround Adobe Forums: How do I troubleshoot Flash Player's protected mode for Firefox?] If you want to test a neutral page first, make sure all Firefox windows are closed, then start up Firefox from the Start menu search box using: firefox.exe "about:blank" If that works normally, then it's something about your home page.