With last update, Firefox let popups open themselves and welcome page is everytime turned into search page "lo.st" instead of google

Hello Melodie. Hopefully these are what you need: http://support.mozilla.com/en-US/kb/How+to+set+the+home+page http://support.mozilla.com/en-US/kb/Searches+are+redirected+to+another+site http://support.mozilla.com/en-US/kb/Pop-up+blocker In any case, it's possible that you are having a problem with some Firefox add-on that is hindering your Firefox's normal behavior. Have you tried disabling all add-ons (just to check), to see if Firefox goes back to normal? Whenever you have a problem with Firefox, whatever it is, you should make sure it's not caused by one (or more than one) of your installed add-ons, be it an extension, a theme or a plugin. To do that easily and cleanly, run Firefox in [http://support.mozilla.com/en-US/kb/Safe+Mode safe mode] (don't forget to select ''Disable all add-ons'' when you start safe mode). If the problem disappears, you know it's from an add-on. Disable them all in normal mode, and enable them one at a time until you find the source of the problem. See [http://support.mozilla.com/en-US/kb/Troubleshooting+extensions+and+themes this article] for information about troubleshooting extensions and themes and [https://support.mozilla.com/en-US/kb/Troubleshooting+plugins this one] for plugins. If you need support for one of your add-ons, you'll have to contact its author. Your problems may also come from malware. To scan for malware, install, update and run these programs ''in this order''. They are all free for personal use, but some have limited functionality in their "free mode", but the features you'll miss are not really needed to find and remove the problem you have. Remember that ''not all programs detect the same malware''! Malwarebytes' Anti-Malware - [http://www.malwarebytes.org/mbam.php malwarebytes.org/mbam.php] SuperAntispyware - [http://www.superantispyware.com/ superantispyware.com] AdAware - [http://www.lavasoftusa.com/software/adaware/ lavasoftusa.com/software/adaware] Spybot Search & Destroy - [http://www.safer-networking.org/en/index.html safer-networking.org/en/index.html] Windows Defender - [http://www.microsoft.com/windows/products/winfamily/defender/default.mspx microsoft.com/windows/products/winfamily/defender/default.mspx] Dr. Web Cureit - [http://www.freedrweb.com/cureit/ freedrweb.com/cureit]

See also http://pagesperso-orange.fr/NosTools/ad_remover.html - Ad_Remover