Version 29 won't finish upgrade

Question

I did the upgrade from V 28.2 to V 29.0. When the upgrade gets to the Compatibility Check it just hang. Never stops. It doesn't even appear in Task Master.
Thinking I might have picked up something, I did a System Restore, then did my normal virus routine. MalwareBytes, Panda A-V, Spybot, etc, all good.
I uninstalled V.29 and reinstalled 28.2. Worked exactly as expected. Blew through the Compatibility Check and started fine
I'm running XP SP 2

Answer 1

Hello,
Please update to the latest service pack available and all updates available for XP and then try a clean reinstall for Firefox to see if it helps as outlined below.
Certain Firefox problems can be solved by performing a ''Clean reinstall''. This means you remove Firefox program files and then reinstall Firefox. Please follow these steps:
'''Note:''' You might want to print these steps or view them in another browser.
#Download the latest Desktop version of Firefox from http://www.mozilla.org and save the setup file to your computer.
#After the download finishes, close all Firefox windows (click Exit from the Firefox or File menu).
#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 [[Installing Firefox on Linux]]. If you downloaded and installed the binary package from the [http://www.mozilla.org/firefox#desktop Firefox download page], simply remove the folder ''firefox'' in your home directory.
#Now, go ahead and reinstall Firefox:
##Double-click the downloaded installation file and go through the steps of the installation wizard.
##Once the wizard is finished, choose to directly open Firefox after clicking the Finish button.
More information about reinstalling Firefox can be found [https://support.mozilla.org/en-US/kb/troubleshoot-and-diagnose-firefox-problems?esab=a&s=troubleshooting&r=3&as=s#w_5-reinstall-firefox here].
<b>WARNING:</b> Do not run Firefox's uninstaller or use a third party remover as part of this process, because that could permanently delete your Firefox data, including but not limited to, extensions, cache, cookies, bookmarks, personal settings and saved passwords. <u>These cannot be recovered unless they have been backed up to an external device!</u>
Please report back to see if this helped you!
Thank you.