The most common problems can be solved in the following ways:
One: Right-click in CHM to see if there is no unlock option ... It's supposed to be locked.
Two: Because the file is in the path name contains # such characters.
Symptoms
After you install security update 896358 or 890175, you may experience one or more of the following symptoms:
• Some types of web-based programs may not function correctly. For example, a table of contents in HTML help may no longer work.
• Some HTML help features may not work when you open a. chm file from a remote location. For example, the related Topics feature might not work.
Open CHM after all the contents are not visible ... Just like our common 404 mistakes!
Note: This article contains supplemental information for the following Microsoft Knowledge Base article:
Vulnerability in 896358 (http://support.microsoft.com/kb/896358/) ms05-026:html help could Allow remote code execution
Vulnerability in 890175 (http://support.microsoft.com/kb/890175/) ms05-001:html help could Allow code execution
These symptoms are expected to occur after you install these security updates. This section provides some examples of administrators who must re-enable HTML help ActiveX controls for critical business programs. These workarounds may endanger computers, making them more vulnerable to threats that are restrained by the aforementioned security updates. The safest way to do this is to not use a registry workaround. If you must use an alternate method, set the registry value as strictly as possible.
Solution:
Paste the following text into a text editor, such as Notepad. The file is then imported into the registry with a. reg file name extension. (Be careful to back up the registry first.)
Code:[copy to CLIPBOARD]REGEDIT4
[HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\HTMLHelp]
[HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\HTMLHelp\1.x\HHRestrictions]
"UrlAllowList" = "\\\\productmanuals\\helpfiles;http://www.wingtiptoys.com/help/"
In addition, Microsoft's own website also has a similar description, the URL is HTTP://SUPPORT.MICROSOFT.COM/KB/902225/ZH-CN
It gives the workaround by referencing
Solutions for end users
Warning: If you are prompted to open or save a. chm file from a Web site, do so only if you need this file and trust the Web site that provides the file.
In the File Download dialog box, click Save, and then select the location where you want to save the. chm file. Then, use one of the following methods:
Method 1
1. Double-click the. chm file.
2. In the Open File Security Warning dialog box, click to clear the Always ask before opening this file check box.
3. Click Open.
Method 2
1. Right-click the CHM file, and then click Properties.
2. Click Unblock.
3. Double-click the. chm file to open this file.
Reprint Source: http://hi.baidu.com/lihonghao_shzh/blog/item/b031dbd38aefc50b3bf3cf86.html