I do not often use Windows so am not the best person to answer this. However I am sure we will get similar questions and an answer soon. I know where the files would be on the Windows 7 etc computers. The bookmarks are not actually part of the Firefox program or in the program files they are your own data. I am guessing but unfortunately it is quite possible the Windows upgrade did not save that sort of data. If you have old files saved or transfered and they are searchable by filename please have a look for the files named ''places.sqlite'' You will have a file with that name for your current Firefox install, are there any others ? ------------ Update Appears likely that there is^[1] an option to save that data. By default Windows 10 probably keeps it for 30 days, and even allows a full rollback to the prior Windows os ^[2] within that time period. # (Windows 7} ''[https://social.microsoft.com/Forums/en-US/a8121d2e-d39a-44ba-ad26-aeb275d302d8/how-to-find-appdata-on-windowsold-computer?forum=learningresources how to find appdata on windows.old computer]?'' # [https://www.reddit.com/r/windows/comments/3f02s1/make_sure_to_run_a_disk_cleanup_after_installing/ctk1o70 link] {Be careful NOT to run the cleanup until you know the files are not needed)

The Firefox profile folder is located here: *C:\Users\<user>\AppData\Roaming\Mozilla\Firefox\Profiles\<profile>\ "AppData" (XP: Application Data; Mac: ~/Library; Linux: ~/.mozilla) is a hidden folder. *http://kb.mozillazine.org/Show_hidden_files_and_folders

Thank you all, I managed to retrieve everything :)