Search Support

Avoid support scams. We will never ask you to call or text a phone number or share personal information. Please report suspicious activity using the “Report Abuse” option.

Learn More

Firefox only opens in full-screen and I can't do anything at all except control-alt-delete and close Firefox!

  • 7 replies
  • 3 have this problem
  • 13 views
  • Last reply by cor-el

more options

Hi. I made a dumb mistake and installed an add-on or extension (not sure which) that I was hoping would allow me to view YouTube videos in full-screen. Unfortunately I can't recall the name of the add-on/extension.

The problem is, now every time I open Firefox it opens in "full screen" and NOTHING (including F11) will allow me to access the taskbar, the address bar, or any of the other Firefox controls. I can't do anything at all but view the home page in full-screen! The only option I have is to hit control-alt-delete and close Firefox.

I tried uninstalling and re-installing Firefox and this didn't solve the problem. Please help. Thank you!

P.S. I'm writing this in Internet Explorer since I currently can't use Firefox.

Hi. I made a dumb mistake and installed an add-on or extension (not sure which) that I was hoping would allow me to view YouTube videos in full-screen. Unfortunately I can't recall the name of the add-on/extension. The problem is, now every time I open Firefox it opens in "full screen" and NOTHING (including F11) will allow me to access the taskbar, the address bar, or any of the other Firefox controls. I can't do anything at all but view the home page in full-screen! The only option I have is to hit control-alt-delete and close Firefox. I tried uninstalling and re-installing Firefox and this didn't solve the problem. Please help. Thank you! P.S. I'm writing this in Internet Explorer since I currently can't use Firefox.

Chosen solution

Try to rename (or delete) the xulstore.json file in the Firefox profile folder.

You can check if you can start Firefox in Safe Mode by holding down the Shift/Options key.

Start Firefox in Safe Mode to check if one of the extensions (Firefox/Tools > Add-ons > Extensions) or if hardware acceleration is causing the problem.

  • Switch to the DEFAULT theme: Firefox/Tools > Add-ons > Appearance
  • Do NOT click the Reset button on the Safe Mode start window
Read this answer in context 👍 1

All Replies (7)

more options

Type about:support in the address bar and press Enter. Under the main banner, press the button; Copy Text To Clipboard.. Then in the reply box at the bottom of this page, do a right click in the box and select Paste. This will show us your system details. No Personal Information Is Collected.

more options

Did you look in "Firefox/Tools > Add-ons > Extensions"?

more options

Hi Fred. Thank you for your reply. Unfortunately, I cannot even access the address bar in Firefox. In fact, like I was saying, I can't do anything in Firefox at all, other than look at my homepage in full-screen. All I can do otherwise is ctrl-alt-delete and close Firefox.

Do you have another suggestion?

more options

Hi cor-el ... Same reply to you as to Fred. I can't do anything at all in Firefox except look at the homepage in full-screen.

more options

Chosen Solution

Try to rename (or delete) the xulstore.json file in the Firefox profile folder.

You can check if you can start Firefox in Safe Mode by holding down the Shift/Options key.

Start Firefox in Safe Mode to check if one of the extensions (Firefox/Tools > Add-ons > Extensions) or if hardware acceleration is causing the problem.

  • Switch to the DEFAULT theme: Firefox/Tools > Add-ons > Appearance
  • Do NOT click the Reset button on the Safe Mode start window
more options

Hi cor-el ... That seems to have done the trick!! Thank you so much for (a) solving my problem and (b) replying so quickly!!!

Take care!

more options

You're welcome