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Local Help Basics

Where is local help? 

The help viewer for VS 2010 is now the default web browser. 
Local help URLs look like

Set Local Help Mode

The default help mode is "Online". To view local help run HelpLibManager.exe and set the help mode to "local".

Run Help Library Manager

Set Local help mode

Now when your press F1 in Visual Studio you should see local help...

Don't See F1 Help?

Still no F1 help showing? Here's a check list you can go through.

Restart Help Library Agent

The Agent tray application runs automatically when you press F1.

Sometimes restarting Agent can clear the problem. To do this right-click the tray icon and select exit. Then press F1 in VS to restart it and display help.

Did you install Local help?

No local help installed will cause 404 Errors.

VS 2010 Express

Usually Express is a web download. This check list is by Jason A. Campbell (MSFT)... Thanks Jason!

Here is a quick overview of the steps you can take:

  1. From within the Visual Basic Express Help menu you should see a "Manage Help Settings" option.  Help Library Manager will start. 
  2. The very first time it starts you will be prompted to give a location to store your help files. 
  3. After that you will be given a list of options
  4. Click on "Install content from online"
  5. Select the books you wish to add to your machine by clicking the "Add" link.
  6. Click on update.

After selecting update the books will be downloaded and installed on your machine.

DVD Install

If you have a DVD of VS 2010 setup then you can simply install local documentation from that and save yourself the 1.x GB of download.

Local documentation is stored on the DVD in the \ProductDocumentation\ folder.

To install local help:
  1. Run Help Library manager (Help menu of VS 2010)
  2. Click "Install content from disk"
  3. Browse to x:\ProductDocumentation\HelpContentSetup.msha
  4. Select and install all local packages

Normal Installation

MS Help Viewer initialization and local help install is done on the last screen of VS 2010 Setup when you hit the blue "Install Documentation" button (not sure if you see this with a Web Install).

One way to install help is run VS 2010 Setup again (you may have missed the blue button first time). 

After running Setup you will need to make a slight change (eg. Add or Remove F#) to get the screen with the blue button to show. Or you can run a full Repair (but this takes a long time).

Press the blue "Install Documentation" button on the last screen.

The first time you run a documentation install you will be asked to confirm the location of the local library store.

Then you will be shown the available local help you can install from the VS Setup DVD.
I assume if you did a VS 2010 web install you don't see this or you are taken to the "Install Content from Online" page instead.

Reset the Help Store

If you are really having problems you could try wiping the local help store and start again.
This can also be used to change location of the local library store.

To clear and reset your local library
  1. Kill Agent off if currently running (using taskbar tray icon).

  2. Delete your current local library store folder (and all it's content).
    The default library location is %PROGRAMDATA%\Microsoft\HelpLibrary\
    • EG. Windows 7: c:\ProgramData\Microsoft\HelpLibrary\
    • EG. Windows XP: c:\Documents and Settings\All Users\Application Data\Microsoft\HelpLibrary\
    • You can check the current Library Location by running Help Library Manager (see screen above).

  3. Edit the file C:\Program Files\Microsoft Help Viewer\v1.0\HelpLibManager.exe.config and set...
    • <add key="FirstTimeRun" value="True" />

  4. Launch Help Library Manager (with the branding parameter if you want the normal VS dev10 branding).
    Tip: You could copy and paste this into Windows Start menu > Run command.
    • "%programfiles%\Microsoft Help Viewer\v1.0\HelpLibManager.exe" /product VS /version 100 /locale en-us /brandingPackage dev10.mshc

Or instead of Step 4 you could run VS 2010 Setup again and hit that big blue button (see above).

Exceptions and 404 Errors

Done everything above and still can't view help?

Tried rebooting, reinstalling, restarting Agent... We need to try something more radical.

Flip between Online and Offline Fix

This post from Dmitry suggests there may be a problem with making the Offline setting stick.

I think I found a solution to this annoying problem. At least it worked out for me.

Here are the steps to fix agent crashes when using local help:

1. Switch to online help using "Help" -> "Manage Help Settings" -> "Choose online or local help".

2. Try online help (like select CString and push F1)

3. Switch to local help using "Help" -> "Manage Help Settings" -> "Choose online or local help".

4. Try local help. It should work now without any crashes (browser should show in the URL to confirm that it is local help)

It looks like that after using online help local help starts working properly. Surprised how MS QA missed this bug.


Agent keeps crashing

There was also a suggestion on the MS forum to add loadFromRemoteSources to HelpLibAgent.exe.config.
It fixes the problem by giving Agent access to the assemblies. However the flip between Online and Offline mode (above) should do the job. 

Try adding the following lines to HelpLibAgent.exe.config

    <loadFromRemoteSources  enabled="true"/>

Unable to access localhost

Andrew posted this in MSDN forums:

I had the same problem, and I figured it out! I have my IIS restricted to a list of IP's because I have another web server running on my Win7, and unless IIS is restricted, it'll take over all the IP's on the machine (it's called socket pooling).

So,  in the registry, go to HKLM/SYSTEM/CurrentControlSet/services/HTTP/Parameters. If you do NOT have a value ListenOnlyList in there, then I do not know why your help agent is not working. If you DO have the ListenOnlyList value, add to its data. You can also delete all the existing entries from the ListenOnlyList value, but then you will get your socket pooling re-enabled, and you most likely have it disabled for a reason...

- restart your computer
- run this from command prompt: net stop http
- start WWW Publishing service

...and the Help Library Agent should start ok now

"Page Can Not Be Displayed"

Vicky Song (MSDN) suggested the following solutions:

In HV 1.0 (help in the browser) you will find that the browser will access which indicates the local machine to get the help. Instead of using the default value, could you please try changing to localhost manually? 

Rob: If using "localhost" instead of works then please see the previous solution for a fix.

In addition, you can also go to the Internet Options>>Connections>>LAN Settings >>
Uncheck the box “Automatically detect settings”.

Rob: This fixed one users who was getting the classic "The page cannot be displayed" being displayed.

Content Renders as raw HTML

Jason Campbell [MS] -- Re “my content renders as raw HTML” threads.  The root cause of this is generally an IE trust issue.  In VS 2010 we could work around the issue by registering our domain ( with the trusted sites.

-- Also from Jason

There is an option in the security Settings of IE "Open files based on content, not file extension" (in old browsers it was called "enable MIME sniffing" in the Miscellaneous section).  On my machine if this was set to Disable for the Internet zone I see the behavior you are describing.

Localhost / again - by Carl Davidson

After doing a complete repair of NET 4 and VS 2010 and reapplying SP1 MS Help Viewer 1.1 still did not work even though I carefully reviewed the notes from http://mshcmigrate.helpmvp.com/faq/init. I decided to try installing VS2010 on a laptop with Vista and help worked fine. I installed H3Viewer and used it for a while (I really like it!). I then noticed that unlike the MS Viewer 1.1, H3Viewer displays the full URL for the local help. I tried that URL in IE on the XP machine and it did not work at first. I remembered in the notes there was and issue with and 'localhost' so I replaced with 'localhost' and the help displayed in the browser just fine. 

I had earlier checked the "Internet Settings/Connections/LAN Settings" page to be sure that the "Automatically Detect Settings" box was not checked and it wasn't. I remembered that there was a check box below it that was checked to automatically run a script so I decided to clear that check box and when I did the help system started working as it should. 

This box was checked and the script that was being run was set by my ISP for the satellite Internet service I am using. Anyone using the WildBlue satellite Internet service may run into the same problem. I hope this will help someone. Thanks for the suggestions Rob.

Alternative Viewer

The default browser view can be frustrating. Try our free H3Viewer which provides a full TOC and full index.

Installing VS Help to Multiple PCs

Copy from one machine to another

If you downloaded the full DVD layout, you should have the '\Product Documentation' folder in it, which will have the content packages and the MSHA file. If you installed VS directly from the cloud, I can recommend an unsupported way of doing this. 

On the other machine, which does not have help content installed locally, please follow the below steps. 

1. Launch Help Library Manager and set your offline content installation path to the same path as the one on the machine where you installed local content. The default path is %ALLUSERSPROFILE%\Microsoft\HelpLibrary.
2. Now, copy %ALLUSERSPROFILE%\Microsoft\HelpLibrary\*.* (or which ever path you configured on the machine where you installed the content) from the machine which has the content installed to the same path in the machine which does not have the content installed. 

Please note that this is not a supported scenario and so, I recommend taking a backup before proceeding with the above steps.

Charles Christian

A Cool downloader by Alexander Kozlenko (SDE, Lime Systems)

Utility for creating Visual Studio 2010 MSDN Library offline installation: 

Downloading MSDN as HxS or CHM

For those who want MSDN in an older format.


Also only a fraction of MSDN ships as .mshc help.

Using this MSDN downloader you could perhaps grab required content and convert to .mshc using .mshcMigrate.

13-Sept-2010: Recently Malcolm Dickson (member of the MS Help team) wrote an extension that allows saving to .mshc format. http://www.codeplex.com/site/users/view/mdickson
You may need to downloaded the patch and recompile the C#.

For more info see Language Packs for Microsoft Help Viewer 1.0 

More Fixes

BITS Download Service

If the Application Event Log mentions BITS then this fix has helped a few people...

To work around this problem by changing the method that the BITS 2.0 client uses to provide logon credentials to the server, create a UseLmCompat registry value in the HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\BITS subkey, and then add a DWORD value of 0. To do this, follow these steps on the BITS 2.0 client computer:
  1. Click Start, click Run, and then type regedit.
  2. Locate the following subkey: HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\BITS
  3. Right-click BITS, point to New, click DWORD Value, type UseLmCompat, and then press ENTER.
  4. In the right pane, right-click UseLmCompat, and then click Modify.
  5. In the Value data box, type 0, and then click OK.
  6. Quit Registry Editor.
  7. Restart the BITS 2.0 service.


Format Problems


Q. I have the Visual Studio 2010 installed and am using the Help Viewer 1.1.  For some reason, last week I lost all formatting.  It is like the css was removed or corrupted.

A. The CSS lives in the branding package. This is located in "Program Files\Microsoft Help Viewer\v1.0\Help3Branding.mshc" for the default branding and "...\v1.0\dev10.mshc" for the Visual Studio 2010 branding. If these files are missing then we will not have CSS. If that is the case I would try repairing visual studio 2010 in add/remove programs to re-write dev10.mshc and/or repairing Microsoft Help Viewer 1.0 to re-write Help3Branding.mshc.

If the files are not missing then the likely cause is that the hosted IE frame is refusing to load CSS for our pages. We originate as ahttp:// request so in general we appear in the internet zone. If your security settings for this zone recently changed to reduce permissions this is a likely cause. If the security settings are ones you would like to keep (most likely) then I you can work around the issue by adding to your trusted sites.

Hopefully this helps,


Problem with PC Network Settings

Whenever I invoke help within VS2010, I get the error "connection refused" by our local gateway.  I put localhost in my hosts file and I can get to the help system with localhost, but not and there is no way to change host name in the Help Library Agent.

Suggested fix:

  • Open this file in notepad -- c:\windows\system32\drivers\etc\hosts
  • You may see a text line such as "::1 localhost"
  • Add a line before this " localhost" (or make sure that is the first line)
  • Or just change the ::1 to

The explanation was that ::1 was expressed in IPV6. Are you using Vista?

Then restart local servers.. in this case Agent tray application.

I Uninstalled Help. I can't reinstall Help.

We install & uninstall help using VS Setup. MS Help Viewer 1.0 is not a standalone install. However if you uninstall help via "MS Help Viewer 1.0" Setup (not VS Setup), then you may find help wont reinstall using the VS Setup program. VS Setup > Repair may show you a blank screen if you try and repair help.

You need to run VS Setup (eg "Microsoft Visual Studio 2010" from Add\Remove Programs from Control Panel), select "Add\Remove Features" (not "Repair") and make a small change in the install options (eg. Remove F#). This will make VS Setup run and at the end of install you will see help install.

VS local help not installed. Now gets 404 error.

A common problem is that some users get to the last page of VS 2010 setup, and do not press the Blue button for installing the VS local documentation. Or maybe s\he presses the blue button but decided not to install the local documentation. For various reasons -- To save disk space; Only plan to use Online help; Thought it was web install and was trying to avoid a large download. etc.

So the help runtime (executables) are installed (VS always installs these), but no documentation is installed and local store may not be initialized.

Apparently the VS local help Home page F1=MSDNSTART is only installed if you add some VS local documentation.
So clicking the VS Help shortcut (start menu) or launching help from the VS help menu produces a 404 page (page not found).


To fix this tell your user to install some local help -- ie. Run HelpLibManager and add one or more local help book (from web or VS Setup disk).

If you are a help integrator then you should provide a link to your help, not the MSDNSTART page. A top level link I like to use (which works with no content installed)  is this one...


Installing Help Documentation

Once VS 2010 Setup completes installation of software and the MS Help Viewer 1.0 runtime, the final screen appears with a blue button inviting you to install the documentation. Click the blue "Install Documentation" button to install VS local help from the DVD. 

If you forgot to install documentation you can rerun VS Setup. The Repair option will display the final page (with the blue button) but takes quite a long time to complete. You can also run VS Setup Add\Remove, but you need to make some minor change (eg. Add F#) to make the final page with the Blue button to appear.