Several days ago I backed up my hard drive, preparing to upgrade from W10 to W11. The upgrade was very slow and took a lot of time. Also, when I began to use W11, many of the programs, including Firefox, were slow to load and slow to run. Finally, I decided to try a reinstall of W11, hoping for an improvement. For this second try, I decide to use the option that eliminated programs that, over the years, I had downloaded onto my computer, such as Adobe Reader, Glary Utilities, and Firefox. For whatever reason, this second installation of W11 took less time and programs like Adobe and Glary worked almost as well as before. (They performed a little better on W10.) But not Firefox! Firefox wouldn’t run at all. I then deleted Firefox, using Revo Uninstaller. My next step was to download another copy of Firefox, from the Mozilla website. The result was the error message I have seen on many postings on this website: Profile Missing Your Firefox profile cannot be loaded. It may be missing or inaccessible. As of this writing, the path C:\Users\rsuth\AppData\Roaming\Mozilla\Firefox\Profiles\ leads to two folders, both dated 11/11/2024: 0dppjrfa.default contains one file, times.json, dated 8/11/2020 and ru82tlj5.default-release, containing 97 items, files and folders, most – but not all - of the files dated 11/11/2024. On my desktop is a folder Firefox Bookmarks. Inside is Mozilla/Firefox/Profiles/xh22l03a.Default User It contains 79 items, files and folders, mostly dated 7/16/2023 I have used Firefox for many years. It contains links to many handy and valuable websites. I hope that someone who has read this account will be able to direct me to a solution that will allow me to recover my previous Firefox and all the all the important information it contains. And, if that happens, then I will try to do something similar with my lost Thunderbird. Thanks for reading.