Q: Crashing on update and losing Itunes completely

Before reinstalling iTunes, make sure that all components have been uninstalled first.  It is important that they are uninstalled in the sequence shown in the following set of instructions.

http://support.apple.com/en-gb/HT1923

For general advice see Troubleshooting issues with iTunes for Windows updates.

The steps in the second box are a guide to removing everything related to iTunes and then rebuilding it which is often a good starting point unless the symptoms indicate a more specific approach. Review the other boxes and the list of support documents further down the page in case one of them applies.

Your library should be unaffected by these steps but there is backup and recovery advice elsewhere in the user tip.

The error hints at a similar pattern to those discussed in the first and third boxes of the user tip, suggesting that you've got an outdated .dll file that needs replacing. You should find CoreMedia.dll in the one of the following folders:

     C:\Program Files\Common Files\Apple\Mobile Device Support

     C:\Program Files (x86)\Common Files\Apple\Mobile Device Support

Delete it and then repair Apple Mobile Device Support from the Programs and Features control panel. If that doesn't work go for the full tear down and rebuild.

tt2

You're welcome.

I'd still recommend that backup if you don't already have one.

tt2