How to solve the problem that the downloaded CHM File cannot display webpages

How to solve the problem that the downloaded CHM File cannot display webpages
Symptoms: Open the CHM file, and the directory on the left is complete, but the webpage cannot be displayed in the border on the right.
Solution:
Method 1: Modify the Registry
1) create a text file
2) Add the following content:
Regedit4
[HKEY_LOCAL_MACHINE \ SOFTWARE \ Microsoft \ htmlhelp]
[HKEY_LOCAL_MACHINE \ SOFTWARE \ Microsoft \ htmlhelp \ 1. x \ itssrestrictions]
"Maxallowedzone" = DWORD: 00000003
Save as htmlhelp. Reg (or another name, as long as it is in Reg format)
3) double-click the newly created reg file and import it to the Registry. OK.
However, this method is not safe because it has changed the browsing area level to 3 and has security risks. Therefore, this method is not recommended.
Method 2: Check whether there is a problem with the directory name. The directory name contains the "#" character. If the CHM File is removed, the display is normal.

Method 3: Sometimes the CHM cannot be opened if it is a Chinese character.

Method 4: double-click the. chm file. In the "open file security warning" dialog box, click to clear the "always ask before opening this file" check box.

Method 5: Right-click the CHM File, click "properties", click "unlock", and double-click the. CHM File to open the file.

The problem I encountered was that some CHM files could not be opened. Use Method 5 to Solve the Problem smoothly.
TIPS: CHM stands for Compiled HTML. A file icon with the CHM extension is usually a document icon with a question mark, indicating a help document. It is a file in the help document format provided by Microsoft since Windows 98, used to replace the HLP (HELP) file in Windows 95. Since Windows 98, Microsoft has built-in interpreters (tools for opening the CHM File) in the operating system, that is, HH. EXE under the Windows installation directory. The CHM file can be generated by providing HTML Help Workshop for free on the official website. Its source file is an HTML file. Nowadays, many e-books on the Internet are produced in chm format.
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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 click "properties ".
2. Click Cancel ".
3. Double-click the. CHM File to open the file.

Solve the problem that the CHM file cannot be opened

After returning from home, I re-installed the system and found that the CHM file that can be opened normally could not be opened. I tried to solve the problem and shared it.

The system version is XP SP2.
Problem: The CHM file cannot be displayed when it is opened.

"Files in chm format cannot be displayed, and files in Windows 2000 are normal. After files are opened on Windows XP, the page cannot be found.

Some CHM files may use the Infotech protocol, which contains three protocols: MS-its, its, MK: @ msitstore. Using these protocols, malicious attackers or hackersCodeAttackers may exploit this vulnerability to control computers. The latest MS Security Update MS05-026 kb896358 corrected this situation and blocked remote links, which led to failure to enable some CHM pages using remote links. The vulnerability is described as follows:

This security issue comes from the Microsoft HTML Help vulnerability announced earlier. HTML help is a standard help system on Windows. The author can use itProgramOr create online help files for multimedia themes or web sites.
Because HTML help does not fully validate the features of input data, this may be exploited. A special CHM file can cause the help system to overflow. If this overflow is exploited, it can be used to execute malicious code.
Such malicious CHM files can be enabled through ie using the "MS-its" protocol. The opened CHM file can automatically execute malicious CHM files and accompanying code without the user's participation. The MS-its protocol is part of the Infotech protocol, which can be executed by itss. dll or Microsoft InfoTech Storage System Library. Of course, these malicious programs cannot be spread by themselves, and users still need to access malicious CHM files at specific locations through IE and "MS-its" protocols.
In this case, if the current logon identity of the affected user is administrator, the remote code execution vulnerability can allow malicious users or malware to gain full control of the affected system.
This allows the malicious user or program to execute code on the system, install or run the program with full control permissions, and view or edit data. Therefore, this vulnerability can also be used for replication.

Affected Systems:

Microsoft Windows 2000 Service Pack 3
Microsoft Windows 2000 Service Pack 4
Microsoft Windows 98
Microsoft Windows 98 Second Edition
Microsoft Windows Millennium Edition
Microsoft Windows Server 2003
Microsoft Windows XP Service Pack 1
Microsoft Windows XP Service Pack 2
Microsoft Windows Server 2003 for itanium-based systems
Microsoft Windows XP-bit Edition Service Pack 1 (itanium)
Microsoft Windows XP-bit Edition Version 2003 (itanium)
Microsoft Windows XP Professional x Edition
Microsoft Windows Server 2003 Service Pack 1
Microsoft Windows Server 2003 with SP1 for itanium-based systems
Microsoft Windows Server 2003 x Edition

The solution is as follows:

[HKEY_LOCAL_MACHINE \ SOFTWARE \ Microsoft \ htmlhelp \ 1. x \ itssrestrictions]
"Urlallowlist" = "\\\ helpfiles \; file: // \\\ helpfiles"

Note that, by default, there may be no itssrestrictions child keys in child Jian 1.x. You need to manually create it and then create the string key value urlallowlist under it.