Please create a screenshot of the problem you're seeing by following the guide mentioned at How do I create a screenshot of my problem?.

Once you've done this, attach the saved screenshot file to your forum post by clicking the Browse... button below the Post your reply box. This will help us to visualize the problem.

Also, make sure to update firefox First. Update Firefox to the latest release

See:

• https://support.mozilla.org/kb/Menu+bar+is+missing
• https://support.mozilla.org/kb/how-do-i-get-firefox-button
• https://support.mozilla.org/kb/why-are-tabs-top

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 or otherwise make changes.

• https://support.mozilla.org/kb/Safe+Mode
• https://support.mozilla.org/kb/Troubleshooting+extensions+and+themes

I add screenshot. If I make FF update at home (windows 7) is all ok, problem is only at work an Windows XP

OK, problem has been solved, problem was with the extension Tab Mix Plus. i have old version of this extension, because at work is not possible make update directly, because I go to the Internet through a proxy. Download, update firefox extension directly via proxy is not possible ... I must download via other internet browser, so do not do it often...