hello zalloy, most search entries for the error message you've provided point to ms visual c++ software as the source of the problem. can you please try the following steps:

go into the windows control panel and uninstall all entries that contain "microsoft visual c++ redistributable". then redownload those packages, which are available at microsoft's website, install them & run windows update afterwards.

Well, I did that, but now when I try to reinstall C++ redist. 2010, it says that it's not the right version for my system. I'm running Windows 7 x64. I should be able to reinstall the 64 bit version of C++, right?

according to the description at microsoft.com the 64bit package is only needed for 64bit applications - firefox is currently only a 32bit application (but it will run on windows 64bit operating systems).

you could also try leaving the c++ redistributable uninstalled for the moment and only install it when a program on your system depends on it - in this case it will throw an error message at program launch pointing you to the correct ms download link. firefox should run & update fine without it.

Oh okay. The other issue is that *none* of the C++ redistributable packages will install. They either come up and say that they're not a valid Win 32 application, or that they are an incorrect version for my operating system, which is Windows 7 Home Professional x64. I'm going to try installing the Firefox update once more.

Same as before. Same error message about the side by side app. Also, the update for Thunderbird won't run either. That one says it's not the right version for my OS. I have Zone Alarm and Malwarebytes running virus scans as we type. I also tried to use the Microsoft scanner, but it wouldn't run. It said it wasn't a valid app. What's going on???

Try to run Sxstrace.exe and create a log file

• http://social.msdn.microsoft.com/Forums/en-US/quebeccomponentsforum/thread/c5073632-0c4a-4c35-8311-de4272079f79
• http://social.msdn.microsoft.com/Forums/en-US/quebeccomponentsforum/thread/c5073632%2D0c4a%2D4c35-8311%2Dde4272079f79
• Sxstrace.exe Trace -logfile:trace.etl

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