hello, first of all please Update Firefox to the latest release in order to get all security fixes & improvements.

firefox stores all your personal data (bookmarks, passwords, etc.) in your profile folder. please refer to the following article which will explain how to recover that: Recovering important data from an old profile

See:

• https://support.mozilla.org/kb/Recovering+important+data+from+an+old+profile
• http://kb.mozillazine.org/Transferring_data_to_a_new_profile_-_Firefox

The Firefox Profile Folder is in this hidden location:

• C:\Users\<user>\AppData\Roaming\Mozilla\Firefox\Profiles\<profile>\

The "Application Data" folder in XP/Win2K and the "AppData" folder in Windows Vista and later Windows 7+ versions are hidden folders.

• http://kb.mozillazine.org/Show_hidden_files_and_folders

madperson,

    Thank you for your reply. Being I'm a computer novice, I got confused with all the options available to possibly solve my problem. These were a few of the options I thought might be applicable? I'm trying to not make my problem any bigger than it is, so choosing the right direction to go is important! Can you please madperson, be more specific in the exact instructions to solve my problem. Of all the options, which option should I choose?
   Secondly, within that catagory, what specific instruction should I pick? Again my problem is, I now have a new windows 7 program replacing the old corrupted one, on my computer. But, the new windows 7 now doesn't have any of my firefox bookmarks from the corrupted windows 7 that was replaced. Simply, how do I specifically reinstall my firefox bookmarks from my old operating system to my now new operating system, with the same computer? 
  Being I have an awful a lot of bookmarks, it is very important to reestablish those bookmarks, to say the least. Can you please madperson take into account my lack of a lot of knowledge with computer solving, and please help? Thank you.

How do I import, export or back up bookmarks?

Switching between different browsers? These article will help you take your bookmarks with you:

   Import Bookmarks and personal data from another browser
   Import Bookmarks from an HTML file
   Export Firefox bookmarks to an HTML file to back up or transfer bookmarks
   Restore bookmarks from backup or move them to another computer 

How do I fix problems with my bookmarks?

Have problems? We have answers:

   Recover lost or missing Bookmarks
   Can't add, change or save bookmarks - How to fix
   Fix "The bookmarks and history system will not be functional" error message

hey, the first & most important step is to find your old firefox profile folder in the backup that is available to you. it's usually in

C:\Users\<your username>\AppData\Roaming\Mozilla\Firefox\Profiles\XXXXXXXXX.default\ 

(also see How do I find my profile?)

when you've found your old profile folder, then there will be a subfolder in it called bookmarkbackups - have look into that and copy the newest backup file that is listed in there and paste it to a location where you can easily access it (like your desktop).

then open your new (&hopefully updated) firefox installation. click on the top left firefox button > bookmarks > import & backup > restore > choose file... and then open the backup-file that you've saved on the desktop before. this should bring back your old bookmarks!

Hi madperson,

    Once again, thank you for your reply. I do appreciate someone willing to help, especially when their lost. I didn't know to access, or what to do with your instruction: C:\Users\<your username>\AppData\Roaming\Mozilla\Firefox\Profiles\XXXXXXXXX.default\ , so I used the instructions: how to find my profile. I did see what I think was a folder icon and specifically "bookmarkbackups".  I clicked on that, and it showed two area's, I choose the latest---Feb. 7, and clicked on it. The message said, windows can't open this folder? While I wasn't able to open it? I did click on "copy" nonetheless madperson. But, and I know this will sound strange to you, how do I paste what I just copied, onto my desktop? What sequence of instructions do I use to accomplish that? It seemed I was able to copy bookmarkbackups, but just where to paste it, and how to paste it left me wondering. Could you please explain where  and how to paste the "bookmarkbackups" I just copied madperson.
      I'm sure hoping this can be worked out through firefox, because the bookmark retrieving method HP suggested, required me to go through every single bookmark (over two hundred of them) and INDIVIDUALLY click on each bookmark and rebookmark that bookmark. It would take me over 3 hours to do that, at least! And, they certainly wouldn't be in the order they were in, and that would take many more hours to accomplish! 
   So, I'm hoping I can get through this situation of finding and reacquiring my old bookmarks and putting them on my new system. Again madperson, I do appreciate your help, and hopefully we can resolve this problem. THANK YOU!

first you copy a file/folder by right-clicking it & selecting copy - then you go to the desktop where you right-click on an empty space & select paste.

madperson,

    Copied bookmarkbackups and pasted them onto my desktop, and followed your instructions: bookmarks > import & backup > restore > choose file. I opened the file. When I opened a new firefox window, I didn't see any of the old bookmarks. Unfortunately, I also lost some of the bookmarks I was saving from yesterday in the process, because when you do this procedure, evidently you lose whatever bookmarks were previously stored. I'm beginning to think because the bookmark backup is dated after my system crash, couldn't find any backup older than before the crash, that the file that is taken and used is not from my system BEFORE the crash? At any rate, no success so far. What suggestions do you have now madperson? Thank you.

from your description it sounds like you've just restored a backup file from your current profile. you'd of course have to restore a backup from before the crash. in your first post you said you have a backup available of your former system, you'd have to obtain the bookmark-backups from this source...

madperson,

    Yes, I do believe this is the case. That is why I was specious of the bookmark backup, the date on it. I know I did a backup shortly after I purchased the computer on a flash drive. and, I hope there is a bookmark backup on it! I will check it out. Also, I did a back up on a DVD prior to the system recovery being performed. So, I know at least there is back up on that device madperson. Nonetheless, I will check the flash drive first and see what that brings. Again, thank you, and I will get back to you after I go into work.

madperson,

    SUCCESS!!!!!!! I used the flash drive, and was able to recover old bookmarks. Those bookmarks were circa 8/28/2012. But, looking at the disc that was used for backup, it was dated just before the system restore function, and it shows more recent history. Nonetheless, I have all my old bookmarks now. What a relief!!! 
    Thank you madperson for your help and patients.