Win7 Open CHM file contents cannot display issue

Today, I downloaded a jquery 1.8.3 Chinese document and found that the exception was displayed after downloading.

Suspicion is the problem of the API, continuously from several sites down a lot of versions, found that there is this problem, and then began to find their own reasons, open the file properties found that the bottom of the file more than the general one content

is the Unlock button, this should be a win7 security mechanism, click Unlock after the display of normal