Are you talking about the default search engines?

You can check if you have the XML files of the default search engines including Google in the browser\searchplugins folder in the Firefox program folder.

If not then you need to reinstall Firefox.

• http://www.mozilla.org/en-US/firefox/all.html

No this is NOT A SOLUTION.

And i already try to reinstall the program but the customized search engines still it was lost so...

Are the XML files of the default search engines present in the browser\searchplugins folder in the Firefox program folder?

I don't have the default search engines i was change it with the search engines i want and these are the search engines i want to backup with any way.

You mean the file "search.json" at this path C:\Users\GRIGORIS\AppData\Roaming\Mozilla\Firefox\Profiles\xxxxxx.default

The search.json file stores the currently installed search engines, both the default search engines in the browser\searchplugins folder an the search engines that you installed yourself in the searchplugins folder in the profile folder.

• http://kb.mozillazine.org/Profile_folder_-_Firefox

If you delete the search.json file then Firefox will create a new search.json file from the default search engines in the "browser\searchplugins" folder in the Firefox program folder and the searchplugins folder in the Firefox profile folder.

As already tallied you i have already try to backup these file/folder and then copy it to the updated firefox ver. 28 but the search engines doesn't come back so....

So, you have all the XML files of the default search engines in the "browser\searchplugins" folder in the Firefox program folder?