You can set Firefox to open on a homepage instead of last tabs fairly easily. Also normally it will open with the option to pen last tabs without problems.

• try to close firefox by using File -> Exit rather than other methods such as killing it with task manager

you may now have a problem with multiple session restore files but try first of all opening and closing firefox normally

Set the Integer pref browser.sessionstore.max_resumed_crashes to 0 on the about:config page to get the about:sessionrestore page immediately with the first restart after a crash has occurred or the Task Manager was used to close Firefox.

• http://kb.mozillazine.org/browser.sessionstore.max_resumed_crashes

That will allow you to deselect the tab(s) that you do not want to reopen, but will allow to reopen other tabs.

See:

• http://kb.mozillazine.org/Session_Restore#Restoring_a_session_after_a_crash
• http://kb.mozillazine.org/Browser.sessionstore.max_resumed_crashes

See also:

• https://wiki.mozilla.org/Session_Restore#Preferences

To open the about:config page, type about:config in the location (address) bar and press the "Enter" key, just like you type the url of a website to open a website.
If you see a warning then you can confirm that you want to access that page.

• Use the Filter bar at to top of the about:config page to locate a preference more easily.
• Preferences that have been modified show as bold (user set).
• Preferences can be reset to the default via the right-click context menu if they are user set
• Preferences can be changed via the right-click context menu: Modify (String or Integer) or Toggle (Boolean)