3 computers with 3 different operating systems: Dell Inspiron Laptop – Windows 8.1, Dell Optiplex Desktop – Windows 7, Gateway 700X – Windows XP. All three computers on the same Firefox account and in sync with each other with no issues. Then I upgraded the Gateway computer to a Dell XPS 8700 with Windows 8.1 due to support for XP being discontinued. I installed Firefox on the new computer and signed on to my Firefox account to sync the bookmarks. Sync was successful but somehow the bookmarks on the new PC did not match the data on the other computers. The bookmarks on the new PC appeared to be old synced data, not recent. So I did the following on the new PC: Disconnected from account and reconnected, Followed instruction on how to add a new PC, Followed instruction on how to add a new device, Uninstalled Firefox and reinstalled, Updated Firefox on all three computers to the latest version, version 32. Nothing helped. Bookmarks on 2 computers are recent and match each other while data on the third one is old and does not match the other two. Interesting thing is that the other two computers with recent bookmark data still sync with each other beautifully. In fact I tested them by changing one of the bookmarks. The other computer immediately synced to it. However, the new computer is stuck with the old data. How do I fix this? How is it possible that all three computers are on the same Firefox account but the new computer only syncs to data that is older than the data on the other two computers? I also noticed that on the new Firefox install the “Sync” tab under "options" looked different than what was on the other computers. On this new install there is no option to pair a device, and "Manage" button in the “Sync” tab looks different. All three Firefoxs are version 32 and downloads were all from Firefox website so I don’t understand why there should be a difference. I don’t know what else I can do. Please help!