The problem with icons being linked to a wrong file has been going on for over 6 years with over 10,000 searches on Google. How do you expect us to upgrade to Win8 when you can't even fix a problem like that for your Win7 users??? Apple would have fixed it immediately.
My experience is, and I work in the IT field, is that issue is caused by, 1) an installed program that resets the file extension properties or 2) User incorrectly sets this himself or 3) Virus or malware. none of these are the fault of Microsoft.
You and MSFT are in denial. Google/Bing the problem and you will see THOUSANDS of WIN7 users with the same problem. I am a 30yr Windows user and retired I/S manager and i am telling you MSFT does not act on customer problems with their products!!