OK, my 1998 Windows XP computer has been retired,\. I now have windows 10 box. On old computer, when I opened Firefox (my default browser) a link to gmail mail appeared on the top left side of the firefox "toolbar." I have searched around for nearly an hour today to figure out how to put that gmail button back at the left side top of firefox and and no luck. Any hints?
Type gmail.com in the address bar, hit enter to go there, cursor up to the stack of books icon in the upper right corner, click Bookmarks and then Bookmark this page. When the little bookmark success window pops up, click the folder pull-down and select Bookmarks Toolbar. Then you can move the Gmail icon wherever on the toolbar you want.
You can also just pin the tab. My Gmail tab is always opened and off to the left. Right click the tab, then click "pin tab". Now it will always open up anytime FF opens.
I have a Chrome browser as well, so if you open a tab in chrome the is a link to Gmail on the home page.