Try disable the Hardware Acceleration:

Try disabling graphics hardware acceleration. Since this feature was added to Firefox, it has gradually improved, but there still are a few glitches.

You might need to restart Firefox in order for this to take effect, so save all work first (e.g., mail you are composing, online documents you're editing, etc.).

Then perform these steps:

• Click the orange Firefox button at the top left, then select the "Options" button, or, if there is no Firefox button at the top, go to Tools > Options.
• In the Firefox options window click the Advanced tab, then select "General".
• In the settings list, you should find the Use hardware acceleration when available checkbox. Uncheck this checkbox.
• Now, restart Firefox and see if the problems persist.

Additionally, please check for updates for your graphics driver by following the steps mentioned in the following Knowledge base articles:

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

• Upgrade your graphics drivers to use hardware acceleration and WebGL

Or try disable onde addon by time then test start the firefox

Did this fix your problems? Please report back to us!

Thank you.

i already tried more then once, before i asked the question, and what is with the download bug when the browser starts?

What does your Firefox download at startup — something you previously downloaded, or tried to download or canceled?

it is always a jpg file, but not the download i did at last before closing, if i download as example an .exe, its still this jpg,

its an temporary because it is from "4chan" its not there anymore. it has always the same filename , but i dont know what picture it is because its a failed download and it has no directory path. even in safe mode it happens

ok, i installed an older version of firefox 24.2.0, the download bug do not appear, if i change to 26 again, the bug is there.

the more important is the slow starting problem, it starts 1000x slower then internet explorer.

There are many things disabled in Safe Mode, as listed in this (unofficial) article http://kb.mozillazine.org/Safe_Mode.

Since your only listed extension is Adblock Plus, I don't think that is likely to be the issue (or thousands of users would have the same problem).

When you start up, are you going straight to your home page?

You said that there was no problem in safe mode? Try this; disable ALL of your add-ons and ALL your plug-ins. See if there is a problem. If not, pick a few (two or three) items to enable. Keep going like this until you have the problem again.

Can you find this file name or the domain from which it originates in the History Manager (Library; History > Show All History)?

i have tried disable all plugins and all addons, it has no effect

i have only one addon installed, adblock plus, i allready tried with uninstall and download new again

Hi arca67, what was the problem you had with the Firefox reset feature? After the reset, Firefox still

• downloaded the unwanted image?
• starts slowly?

When Firefox is starting, is it restoring your previous session windows and tabs, or going straight to your home page?