I have compiled information that I found on different websites that ultimately allowed me to fix the msvcr80.dll error on both Windows 7 and Windows XP. I have yet to figure out what underlying issue is common on all the computers getting this error, but one of my hunches is that some computers with old versions of MobileMe may run into a problem when iTunes tries to update itself.
Using system restore made no difference with the existing issue. A simple reinstall from download didn’t either. Note that I always disable the antivirus during installs and uninstalls with programs of this complexity. The best advice I found wasn’t on Apple’s forums, it was by a guy named Tim Fisher at http://pcsupport.about.com/od/findbyerrormessage/a/msvcr80-dll-not-found-missing-error.htm. I followed his instructions:
“Uninstall from Windows the following programs in this order: iTunes, Apple Software Update, Apple Mobile Device Support, Bonjour, Apple Application Support, iCloud, and finally MobileMe.” On Windows 7, I ran into a problem when I got to Apple Mobile Device Support. Whether I tried to uninstall or change (and then uninstall), it would always roll back on me and fail.
A forum suggestion recommended getting the Microsoft uninstall Fixit utility, found at http://support.microsoft.com/mats/Program_Install_and_Uninstall. I launched this utility and selected the Apple Mobile Device Support to be uninstalled and let the utility start. This program ran and ran and ran. I was beginning to wonder if it was doing anything, and started monitoring it in task manager. At times, it would utilize over 7GB or physical memory on a computer that had 8GB with CPU utilization over 25%.
I finally got tired of waiting and went to the control panel while the Fixit utility continued to run. I clicked on Apple Mobile Device Support and attempted to uninstall again. This time it reported that it had already been uninstalled and the entry was removed from the program list. I took this as a good sign. I continued uninstalling the programs in the order recommended, all while the Fixit utility continued to run in the background. I know that might have been a gamble, but I didn’t have all day to see if it would finish.
After everything else was uninstalled, I rebooted the computer and downloaded iTunes again and proceeded to do the clean install. I prayed to the gods of Zeros and Ones when it got to the point where it needed to start services. You may have noted that this is where reinstall previously went south. Voilà! Success.
I hope the above information helps someone, especially if they run into a few hiccups like I did. Good luck.