If you only need to save bookmarks, try this:

Open your current Firefox settings (AKA Firefox profile) folder using

Help > Troubleshooting Information > "Show Folder" button

In the folder that opens, double click the bookmarkbackups folder.

Copy all the files here to a safe location, e.g., USB flash drive, your Dropbox account, attach to an email and send to your webmail account, etc. Although in theory you only need the latest one, in case that is corrupted, take them all.

If other data is also of interest, such as history, saved passwords, add-on settings, etc.:

You may want to copy more files. This article may help in identifying what would be useful later: Recovering important data from an old profile.

Finally, you could consider this program, which I haven't tried myself: MozBackup - Backup tool for Firefox and Thunderbird.

On second read, reinstalling doesn't usually have much effect unless the program files have become corrupted somehow. Did you try this article: Firefox can't load websites but other browsers can?

Hello J, That was a fantastic reference. I ran into this problem years ago and somehow, after a long night, I bumped into the solution. Following your advice (also your hint helps below on the bookmarks) was to the point and is useful for future incidences so I've saved the page to my desktop. Thank you so much! I really appreciate you taking the time, being so prompt and for sharing your knowledge. Elaine