Check and see if you have any add-ons for Yahoo. Also check your computers installed programs. '''Windows Start > Control Panel > Uninstall Program'''. After, check your computer for malware (see below).<BR><BR> Open a new window or tab. In the address bar, type '''''about:config'''''. If a warning screen comes up, press the '''''Be Careful''''' button. This is where Firefox finds information it needs to run. At the top of the screen is a search bar. Enter '''''browser.newtab.url''''' and press enter. '''''browser.newtab.url''''' tells Firefox what to show when a new tab is opened. If you want, right click and select '''''Modify'''''. You can change the setting to;<BR><BR>about:home (Firefox default home page),<BR> about:newtab (shows the sites most visited),<BR> about:blank (a blank page),<BR> or you can enter any web page you want.<BR><BR> The same instructions are used for the new window setting, listed as '''''browser.startup.homepage'''''. =============================================== Sometimes a problem with Firefox may be a result of malware installed on your computer, that you may not be aware of. You can try these free programs to scan for malware, which work with your existing antivirus software: * [http://www.microsoft.com/security/scanner/default.aspx Microsoft Safety Scanner] * [http://www.malwarebytes.org/products/malwarebytes_free/ MalwareBytes' Anti-Malware] * [http://support.kaspersky.com/faq/?qid=208283363 TDSSKiller - AntiRootkit Utility] * [http://www.surfright.nl/en/hitmanpro/ Hitman Pro] * [http://www.eset.com/us/online-scanner/ ESET Online Scanner] [http://windows.microsoft.com/MSE Microsoft Security Essentials] is a good permanent antivirus for Windows 7/Vista/XP if you don't already have one. Further information can be found in the [[Troubleshoot Firefox issues caused by malware]] article. Did this fix your problems? Please report back to us!