First, let's make sure your system is clean.

Further information can be found in this article; https://support.mozilla.org/en-US/kb/troubleshoot-firefox-issues-caused-malware?cache=no

Run most or all of the listed malware scanners. Each works differently. If one program misses something, another may pick it up.

Your user profile contains all your browser information.

Open the Bookmarks Manager; Press the Alt or F10 key to bring up the toolbar, and select Bookmarks. Hot key is <Control> (Mac=<Command>) <Shift> B.

Is the information here? If not, you may be looking at a replacement profile.

Look on your desktop. Do you see a folder called; Old Firefox?

https://support.mozilla.org/en-US/kb/recovering-important-data-from-an-old-profile

https://support.mozilla.org/en-US/kb/back-and-restore-information-firefox-profiles

https://support.mozilla.org/en-US/kb/how-run-firefox-when-profile-missing-inaccessible

konaboy11 said

I had a virus in my Firefox browser, and I had to delete the program.

What was involved in that process? Firefox stores your bookmarks on your disk drive under the hidden AppData folder. Normally if you simply run the Firefox uninstaller, that data remains and is used automatically when you reinstall Firefox. If it's still there somewhere, we can help you track it down.

However, if you used some system or third party cleaning tools to scrub out everything related to Firefox, you may not be able to find your bookmarks. In that case, an "unerase" tool might be helpful. For example: http://www.piriform.com/recuva