I recently got a new computer and I am having a problem installing Firefox. In the installation wizard, the last step gives the option to launch Firefox after you click finish, but no window opens. I click on the shortcuts, navigate to the .exe file, use Window's Run tool and nothing will launch Firefox. I am also unable to launch Firefox Profiles Manager using Windows Run tool. Each time I click the Firefox shortcut, another instance of firefox.exe appears in my Windows Task Manager under Processes. I have uninstalled Firefox (including removing the profile folders/all personal data), but the same issue occurs when I install Firefox the next time. This is a brand new computer running Windows XP, Service Pack 3 (I am unable to use Windows 7 due to work application compatibility constraints). When I first turned it on this morning, I was able to install and run Firefox. I loaded my profile using Firefox Sync from my old computer to my new computer. Everything was running perfectly, I could pull up the tabs from Old Comp onto New Comp. All my passwords and bookmarks transferred. Everything fell apart after I installed an Adobe Flash plugin required for one of my bookmarked pages. The Flash installation required me to close Mozilla, and it has never re-opened since. I have uninstalled all the Adobe flash plug-ins I can find using the Add/Remove Programs tool. I have restarted the computer several times, uninstalled and re-installed Mozilla, and tried everything else I can think to do. What could be prevent Firefox from launching at this point? What should I try next, short of reformatting the entire computer and reinstalling Windows?