You start iTunes and get the following error:
The program can’t start because AVFoundationCF.dll is missing
That seems that your either trying to use a portable iTunes version (none of which really work) or your iTunes copy got corrupted by Apple Update.
The solution is the same though: browse to Start – Control Panel -> Programs and features, select Apple Application Support and click Repair.
Alternatively, you may remove Apple Application Support, download iTunes..setup.exe, unpack it with 7-Zip and reinstall AppleApplicationSupport.msi