Hi Rob, that's a rare error code here on the forums. The only confirmed solution I saw was to use Firefox's Refresh feature ([[Refresh Firefox - reset add-ons and settings]]). Let's poke around a bit first. You can get a rough idea of what new software might have been installed using the Windows '''Control Panel''', Uninstall a Program. After the list loads, click the "Installed on" column heading to group the infections, I mean, additions, by date. Anything unknown or suspicious? Malware often uses important or innocent sounding names to discourage you from removing it, so I suggest taking out as much trash as possible here. In coordination with your wife, of course. You might also check for any unexpected add-ons. Open Firefox's '''Add-ons page''' using either: * Ctrl+Shift+a * "3-bar" menu button (or Tools menu) > Add-ons * in the Windows "Run" dialog, type or paste <br><code>firefox.exe "about:addons"</code> In the left column, click '''Plugins'''. Set nonessential and unrecognized plugins to "Never Activate". In the left column, click '''Extensions'''. Then, if in doubt, disable (or Remove, if possible) unrecognized and unwanted extensions. ''All extensions are optional; none come with Firefox.'' Often a link will appear above at least one disabled extension to restart Firefox. You can complete your work on the tab and click one of the links as the last step. Any difference? If you suspect possible foul play, you can supplement your regular security software with the '''scanning/cleaning tools''' listed in our support article: [[Troubleshoot Firefox issues caused by malware]]. These on-demand scanners are free and take considerable time to run. If they finish quickly and especially if they require payment, you may have a serious infection. I suggest the specialized forums listed in the article in that case.