Is there a reason you want this?

https://support.mozilla.org/en-US/kb/changes-toolbars-and-window-sizes-are-not-saved Removing these files will make the browser 'forget' the current window size and location; xulstore.json or Localstore.rdf

Close Firefox. Open your file browser to this hidden location:

• Mac: *~/Library/Application Support/Firefox/Profiles
• Linux: *~/.mozilla/firefox/Profiles
• Windows: %AppData%\Mozilla\Firefox\Profiles
• *C:\Users\<user>\AppData\Roaming\Mozilla\Firefox\Profiles
• Windows XP: C:\Documents and Settings\<user>\Application Data
  \Mozilla\Firefox\Profiles\

Search for the above files. Then rename or delete them. Restart Firefox.

There is no Localstore.rdf (anywhere on my PC) and when I remove xulstore.json it's regenerated after I open FF and the cycle starts again....

I have multiple monitors all around me, some even behind. When I move the browser to a location on my extended desktop, the next instance of FF I open will occur at around the same coordinates and size.

Therefore, the last place I move FF to which could be my large display 90 degrees to the side of my main display. I have to turn my head to the side and move FF back to my main display if I want to use it there.

Am I missing something major, how is this not a fundamental option of FF for multi monitor users?

Is there an option to open each new instance of FF on the main display, if so where is it?

Thanks kindly for trying to help.

That's above me. I called for more help.

Thank you for investigating,

Initially this was less frustrating with fewer monitors. I have to look all over my studio for which monitor has FF when I open a new instance each time. There are times I have to switch out of extended mode to computer only just to track FF. Very inconvenient to say the least.

Take MPC-HC for example. It has the option to remember last window position. That makes it possible to open the app on the main display by default each time. There is even a 2nd option to remember last widow size. The two combined are ideal.

The current new window default behavior is to open the new window in the last active Firefox browser window/monitor. It will take the same size as the last active window and will open in the last active monitor. This is what I have observed on a Mac OS.

Now when I tried it for the Windows 7 machine it had a similar behavior. However, what I found based on the operating system in your question that there is also a behavior in Windows that opens the application in the last active monitor the program was in. (Maybe this is behavior for both Firefox and Windows 7? ) This was the suggested: https://community.spiceworks.com/topi.../366672-dual-monitors-windows-7-assign-apps-to-a-monitor?page=1#entry-2416856

Thanks for replying guigs but none of the info is truly useful to me.

I need to know if FF is hardcoded with a 'remember last location' option so it will allow us to open in main display by default when we do not want FF to open a new instance at the last coordinates it was set to. I don't have an issue with opening apps in secondary monitors. I just want FF to open in the main display preferably in a usable size such as when file xulstore.json is deleted.

I thought my question could be easily solved via about:config perhaps.