Which version of Firefox are you currently running?

If you are running 49.0.1, please try installing version 49.0 instead.

I have completely deleted mozzilla firefox off my computer using the uninstalled tool from firefox themselves. then restarted my computer. I then tried to reinstall firefox using the link and version you suggested.... the only think that happened when I opened the firefox 49.0 set up was files extracted and that was it. It did not install the browser onto my computer... I am at a loss for how to correct the problem. at least prior to me using the uninstaller tool the browser was actually on my computer and opened, it just crashed right away .

When you say "Firefox crashes", do you see a "crash window" or nothing happens ?

Do you see the process firefox.exe running in Windows Task Manager ?

well it not crashing anymore because ever since I ran the uninstaller (from firefox) I have not be able to reinstall any version on my compuiter. I have tried the following exe's directly from mozilla.....

setup (44.0) , (45.0) , (47.0) , (48.0) , (49.0) and... stub (44.0) , (45.0) , (47.0) , (48.0) , (49.0) none of these complete the instalaion and I am not able to find the any file listed on windows program files through control panel

Certain Firefox problems can be solved by performing a Clean reinstall. This means you remove your Firefox program files and then reinstall Firefox. This process does not remove your Firefox profile data (such as bookmarks and passwords), since that information is stored in a different location.

To do a clean reinstall of Firefox, please follow these steps: Note: You might want to print these steps or view them in another browser.

1. Download the latest Desktop version of Firefox from mozilla.org (or choose the download for your operating system and language from this page) and save the setup file to your computer.
2. After the download finishes, close all Firefox windows (or open the Firefox menu and click the close button ).
3. Delete the Firefox installation folder, which is located in one of these locations, by default:
   • Windows:
     • C:\Program Files\Mozilla Firefox
     • C:\Program Files (x86)\Mozilla Firefox
   • Mac: Delete Firefox from the Applications folder.
   • Linux: If you installed Firefox with the distro-based package manager, you should use the same way to uninstall it - see Install Firefox on Linux. If you downloaded and installed the binary package from the Firefox download page, simply remove the folder firefox in your home directory.
4. Now, go ahead and reinstall Firefox:
   1. Double-click the downloaded installation file and go through the steps of the installation wizard.
   2. Once the wizard is finished, choose to directly open Firefox after clicking the Finish button.

More information about reinstalling Firefox can be found here.

WARNING: Do not use a third party uninstaller as part of this process. Doing so could permanently delete your Firefox profile data, including but not limited to, extensions, cache, cookies, bookmarks, personal settings and saved passwords. These cannot be easily recovered unless they have been backed up to an external device! See Back up and restore information in Firefox profiles.

Please report back to say if this helped you!

Thank you.

i have done every step in the order you stated. still having the problem. I am going to run another deeper scan of all files on my computer for viruses etc. after doing that. i will attempt once again in the above mentioned order and report back. thank you for all you help everyone.

after running a deep scan for viruses on my computer I found I did have one! which ( I assume) is the reason I wasn't unable to reinstall firefox even using the link Wesley suggested. since removing the infected files and rescanning I was able to install firefox from the link!!! (49.0) it worked great the first 2 times I opened the browser, now I am getting the message that windows has detected a problem and needs to close firefox and it shuts down. UGGH!

We're sorry to hear that your Firefox seems to be crashing when you open it. Please perform the following steps to give us a crash report ID that helps us find out more about the cause of the crash.

1. On the keyboard, press [Windows] The image "Windows key" does not exist. + [R]. This should bring up a Run window that contains a text field.
2. In that text field, type %APPDATA% and press Enter. An explorer window should open.
3. From that explorer window, double-click on the Mozilla folder, then double-click on Firefox and then on Crash reports. Double-click on submitted.
4. Now, you should see a list of files that contain reports. Go to View > Arrange Icons by > Modified to get the most recent files at the top of the window.
5. Open the most recent 5 files with a text editor and copy the IDs.
6. Paste each ID with bp- into the reply window on the forums.

Thanks in advance!

You can find more information and troubleshooting steps in the Troubleshoot Firefox crashes (closing or quitting unexpectedly) article.

Crash ID: bp-933c27f4-1667-4361-b8e0-58d272160914 Crash ID: bp-7400b8c3-b88f-4bc8-b6f1-2f4d02160928 Crash ID: bp-190e0db4-9984-4c4b-af77-c5eb32160822 Crash ID: bp-b6f4980f-c4be-47c2-84ee-daa9b2160829 Crash ID: bp-d220ff1a-74b5-4c5a-9ac0-646672160928