The fjlwfj09.default is your new account? You don't need a new account. Just copy the old profile over but so its in the same sub-folder as the current one.
just to clarify, as the actual paths seem to be given for XP above,
you want to delete C:\Users\Jim\AppData\Roaming\Mozilla\Firefox\Profiles\fjlwfj09.default
and replace it with C:\Users\Jimmy\AppData\Roaming\Mozilla\Firefox\Profiles\vj4ammer.default
note that your screenshots have Local where they should have roaming.
If there isn't a Firefox process in Task Manager, take a look at this.