Firefox doesn't keep a backup of the History like is done with the bookmarks.

Windows may have created a shadow copy of the places.sqlite file and in that case you can try to restore a previous copy is there is one of a suitable date and time. Make sure to backup the current places.sqlite file.

• Right-click: Properties > Previous Versions
• http://windows.microsoft.com/en-US/windows7/Previous-versions-of-files-frequently-asked-questions

You can use this button to go to the currently used Firefox profile folder:

• Help > Troubleshooting Information > Profile Directory: Show Folder (Linux: Open Directory; Mac: Show in Finder)
• http://kb.mozillazine.org/Profile_folder_-_Firefox

I've attached a picture and that's the library now. The History tab should have the "yesterday, today, last 7 days" right? So mine is empty. And the downloads is also gone. I don't know where it is unless I clicked the download sign and open the containing folder. I only have the bookmarks tab.

You can check for problems with the places.sqlite database file in the Firefox profile folder.

• http://kb.mozillazine.org/Bookmarks_history_and_toolbar_buttons_not_working_-_Firefox
• https://support.mozilla.org/kb/Bookmarks+not+saved#w_fix-the-bookmarks-file

• Places Maintenance: https://addons.mozilla.org/firefox/addon/places-maintenance/

It worked! I just have to delete that sqfile to restore it. Thank you so much. Thanks mate!