Clear the cache and the cookies from sites that cause problems.

• "Clear the Cache": Tools > Options > Advanced > Network > Offline Storage (Cache): "Clear Now"
• "Remove the Cookies" from sites causing problems: Tools > Options > Privacy > Cookies: "Show Cookies"

i tried this and the menus still not appearing :(

Start Firefox in Diagnose Firefox issues using Troubleshoot Mode to check if one of the add-ons is causing the problem (switch to the DEFAULT theme: Tools > Add-ons > Appearance/Themes).

• Don't make any changes on the Safe mode start window.

See:

• Troubleshoot extensions, themes and hardware acceleration issues to solve common Firefox problems

i tried this also not working i want to cry :(

Any chance you are looking at the default Firefox homepage - about:home?

That "page" is built into Firefox 4.0 and looks like what Firefox 3.6 and earlier versions had for the default homepage -http://www.google.com/firefox - but isn't the same.