Itunes won't install. An error occurred during the installation of assembly 'Microsoft.VC80.CRT,version=" 8.0.50727.6195",type="win32",publicKeyToken='1fc8b3b9a1e18e3b",processorarchitec ture="x86". Please refer to Help and Support for more information.

These ones are typically caused by underlying problems on the PC that also often cause Windows Updates to fail to install. If we can fix the Windows Update trouble, we can usually get the iTunes trouble cleaned up en passant.

Go into your Windows update and try to check for new updates. If updates install, stock up on the ones you're behind on, restarting the PC if requested to do so. After the restart, try installing iTunes again. Does it go through this time for you?

If windows updates fail to install, go into your Update History and doubleclick the failures. What alphanumeric codes appear for you? (For example, 8007000B.)

Sorry about the delay.

The 80080005 isn't my favorite number to see in this context. If we're lucky, it might just be because the BITS service is disabled, but otherwise it suggests something exotic about your Windows Modules Installer.

Perhaps try the Fixit center at Microsoft, first? (Fingers crossed one of their Windows-Update-related automated fixits is worth a try here:

http://fixitcenter.support.microsoft.com/Portal/WhyFixIt

Drat.

I think we'd better try to get you on the radar screens of some Windows Update specialists.

Try reposting over at Microsoft Answers, in their Windows Update category:

http://answers.microsoft.com/en-us/windows/forum/windows_update

Let them know about the 80080005 code, and also that you've tried the Fixit Center. (Fingers crossed that'll head off people just pointing you to the Fixit Center again.