How to solve the CHM File opening problem in win7

Source: Internet
Author: User
Tags microsoft website

Very practical, original address:

I encountered a very difficult problem today. I wanted to see the materials but could not open the CHM help file.
I installed 64-bit win7. When I open the CHM file, the system prompts me a security problem and forcibly opens it, but the content cannot be displayed. The prompt is "This page navigation is canceled ", depressed, with a headache. What should I do? It's so anxious ......
You only need to ask Google for help.
I looked at it. It was very troublesome. I had to modify the Registry. If I accidentally did this, it would crash. That's hard.
However, there is no way to solve the problem. The job is not waiting for anyone.
Fortunately, after my unremitting efforts and my talents, I finally found the simplest and most effective solution. .. No worries...
Now I will post this method to share with you.

1. Open CHM
2. Windows 7 prompts security questions
3. The CHM cannot display the content.
4. Disable CHM
5. Right-click CHM and click "unlock". OK is not "unlock" and dizzy... Please go down
6. Right-click CHM and click "compress to *. rar" to compress CHM.
7. Double-click the generated compressed file *. rar
8. Double-click CHM in rar to open the file. OK. Everything is available.
9. Problem Solving

It's easy.

Below we post a post on the Internet with a super complex method for your research.

1. If the prompt is: Internet Explorer cannot be linked to the webpage you requested or the page cannot be displayed after it is opened ".
Right-click the attribute on the CHM File to open, and a "unlock" button will be added to the attribute below. After you click it, the attribute will be displayed normally.
Or save the following content in Notepad as 00.reg:
Regedit4 [HKEY_LOCAL_MACHINE \ SOFTWARE \ Microsoft \ htmlhelp] [HKEY_LOCAL_MACHINE \ SOFTWARE \ Microsoft \ htmlhelp \ 1. X \ hhrestrictions] "maxallowedzone" = DWORD: 00000003 "urlallowlist" = "" [HKEY_LOCAL_MACHINE \ SOFTWARE \ Microsoft \ htmlhelp \ 1. X \ itssrestrictions] "maxallowedzone" = DWORD: 00000003
"Urlallowlist" = ""
Copy the preceding content to a text file, change the file name suffix to. Reg, and click

2. If the message "cannot open the file MK: @ msitstore :\****. CHM "may cause this fault because it is hhctrl in your system. OCX files are lost or are hhctrl. if OCX is overwritten, you can copy one from the same computer or the installation disc and register hhctrl again. ocx file: The procedure is as follows: Step 1: Exit all running programs and click Start> program. Step 2: In the run dialog box, type "regsvr32 C: \ WINDOWS \ SYSTEM \ hhctrl. OCX "press enter, or" regsvr32/I hhctrl. OCX "the message" dllregisterserver succeeded "is displayed. restart the computer.

Iii. Other Methods
1. Go to "language and Region"-"region options" from the control panel of windows. if the region is not Chinese, change it to Chinese.
2. simply change the file name to E (. CHM), copy it to a root directory, open it and check if it doesn't work. Please download it again. Sometimes there is a problem with the download process and check whether it is OK.
3. If most CHM cannot be opened, try registering regsvr32 itss. dll again.
(1) Right-click to associate the "open mode" of the CHM File to \ windows \ hh.exe
(2) Run regsvr32 itss. dll on the command line.
(3) Run regsvr32 hhctrl. ocx on the command line.
(4) start -- run -- Enter "Regedit", open the registry, and find the following branch: HKEY_LOCAL_MACHINE \ SOFTWARE \ Microsoft \ htmlhelp \ 1. create a DWORD key maxallowedzone under X \ itssrestrictions, and set the value to 3.
5. You have not installed the supervisor or deleted the hh.exe file. You can check it under windows \ system32. If this is the case, you can copy a hh.exe file from someone else's computer, put it in the directory above, and double-click a CHM file so that you can select the c: \ windows \ hh.exe program, which restores the association between the chmfile and hh.exe.
Download hhupd.exeon the Microsoft website, install hh.exe, and run it. 2. Download hhupd.exe and run it. The size of this item is 461kb 3. in c: \ windows \ system32, find "hhctrl. ocx file, and then run: "regsvr32 c: \ windows \ system32 \ hhctrl. OCX...
6. Delete "HH. dat" in the directory \ Documents ents and Settings \ % username % \ Application da if the preceding conditions are good.In ta \ Microsoft \ HTML Help, this file contains some content that may cause errors.

4. Start -- run -- Enter "Regedit", open the registry, and find the following branch: HKEY_LOCAL_MACHINE \ SOFTWARE \ Microsoft \ htmlhelp \ 1. create a DWORD key maxallowedzone under X \ itssrestrictions, and set the value to 3.

If you delete the hh.exe file, you can check it under windows \ system32. If so, you can copy a hh.exe file from another computer, put it in the directory above, and double-click a CHM file so that you can select the C: \ windows \ hh.exe, the association between the chmfile and hh.exe is restored.
6. If the preceding conditions are good, delete "HH. dat" in the \ Documents ents and Settings \ % username % \ Application da directory.In ta \ Microsoft \ HTML Help, this file contains some content that may cause errors.
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. I just got back from home and re-installed the system. I found that the CHM file that can be opened normally could not be opened. I tried to solve it myself and sent it out for sharing. The system version is XP SP2.
Problem: When a CHM file is opened, the "chm format" file cannot be displayed, and Windows 2000 is normal. After the CHM file is 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 malicious code may cause an overflow vulnerability to help 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 it to create online help files for programs, multimedia themes, or websites. 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 generation. Such malicious CHM files can be enabled through ie using the "MS-its" protocol. After the CHM File is enabled, the malicious CHM file and the accompanying generation can be automatically executed 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 malicious software 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 to repeat
Solution: [HKEY_LOCAL_MACHINE \ SOFTWARE \ Microsoft \ htmlhelp \ 1. X \ itssrestrictions] "urlallowlist" = "[url =] \\\ helpfiles \; file: // \\\ helpfiles [/url]"

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.

Method 3
When the CHM file path contains "#" "%" and other characters, the CHM file can be opened but cannot be displayed.
The reason is: Opening the CHM File is equivalent to entering a command line statement containing the file path and executing it. After "#" % "and other characters are inserted in the path, the syntax of the command line changes, leading to the failure to use CHM normally. At this time, the system will not prompt errors, so many people are troubled. Haha, my C # Is because of this #. Delete the problem and solve it.
Solution: Delete special characters in the path.

Method 4
After installing Microsoft's Security Update 896358 or 890175, the patch limits CHM's itss protocol. Some CHM use this protocol, so the CHM cannot be displayed.
Solution: you can modify the registry, security level, and itss. dll (this is what I heard );

Method 5
Modify registry
1) create a text file
2) Add the following content:
[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 6
Check whether there is a problem with the directory name. The directory name contains the "#" character. If the CHM File is removed, it is displayed as normal.

Method 7
Sometimes the CHM cannot be opened if it is a Chinese character.
Method 8
Right-click the CHM File, click "properties", click "unlock", and double-click the. CHM File to open the file.

Method 9
If none of them work, convert the chm format of the ebook to a PDF file:
Here is a piece of software:
CHM converter is a file that converts CHM files into common formats such as PDF, txt, and Doc.
After downloading and running the software, the default software interface is English. You can click "tools-language" in the menu and select "chinese_simplified" in the pop-up dialog box to change it to Chinese, the software also supports many other languages.
After selecting the language, click "open" in the upper left corner to select the CHM file to be converted. If the CHM file is in English, select "defailt_charset" from the drop-down menu next to it ", if it is a Chinese character, select "gb2312_charset" from the drop-down menu. Otherwise, garbled characters are generated and the file type to be converted is selected from "Export" on the right, the software supports many formats of files, such as here select "Word97-2003", and finally click "Save database as" button, select the Save folder and start to convert.

Contact Us

The content source of this page is from Internet, which doesn't represent Alibaba Cloud's opinion; products and services mentioned on that page don't have any relationship with Alibaba Cloud. If the content of the page makes you feel confusing, please write us an email, we will handle the problem within 5 days after receiving your email.

If you find any instances of plagiarism from the community, please send an email to: and provide relevant evidence. A staff member will contact you within 5 working days.

A Free Trial That Lets You Build Big!

Start building with 50+ products and up to 12 months usage for Elastic Compute Service

  • Sales Support

    1 on 1 presale consultation

  • After-Sales Support

    24/7 Technical Support 6 Free Tickets per Quarter Faster Response

  • Alibaba Cloud offers highly flexible support services tailored to meet your exact needs.