Several windows open
On launching firefox browser on PC, the computer slows. I opened Task Manager to close unnecessary tasks and there are around 10 firefox windows open (which I didn't open). There is only one firefox window/tab visible. On going to settings the restore previous session box is greyed out. Underneath it says my default browser is firefox.
Moambuepyre
Opaite Mbohovái (1)
It's possible that Firefox is set to restore your previous session upon launch, which is causing the multiple windows to open. To disable this, go to Firefox settings, click on "General" and change the "Startup" option to "Show your home page" or "Show a blank page". Additionally, you can try clearing your browsing history and cache to improve Firefox's performance.