I know banks like Chase and Citi has fairly recently required Firefox 128.0 or later to use the sites. Since you appear to have the eol Windows the most current version you can run is Firefox 115 ESR currently at 115.31.0esr. Firefox 116.0 and later requires Windows 10, 11 to run. https://support.mozilla.org/en-US/kb/firefox-users-windows-7-8-and-81-moving-extended-support If you cannot update your Windows to 10 or 11 to use the current Firefox versions, then there is something you can try to fool the bank sites into thinking you have a more current version. The more technical option may be to dual boot with a current version of a Linux distro. # In a new tab, type or paste '''about:config''' with a colon : in the Location (address) bar and press Enter/Return. Click the button accepting the risk. # In the search box on top of the page, type or paste forceVersion and pause while the list is filtered # Double-click the ''network.http.useragent.forceVersion'' preference to display an editing field, and change the value to '''128''' or '''140''' then press Enter/Return or click the blue check mark button to save the change.