Can an old CHM file be updated to work with Windows 10?

Question

I am using the Windows 10 Enterprise OS. I have a help file in CHM format that cannot be opened in a Windows 10 box. All it says is "Failed to launch help." I wrote a tiny program to try this. Here's the important bit of code:

void CHelpFileTEstDlg::OnBnClickedButton1()
{
    CWinApp* pApp = AfxGetApp();
    AfxMessageBox(pApp->m_pszHelpFilePath);
    pApp->m_pszHelpFilePath = _T("C:\\Dev\\LD\\RSLogix5000\\BuildProducts\\Debug\\PSModuleENU.chm");

    AfxMessageBox(_T("Does this help button work?"), MB_YESNO | MB_HELP | MB_ICONEXCLAMATION, 196743);
}

When I click the Help button, I get the same "Failed to launch help." message, but also, a web page appears in my browser saying that help system I'm using is not support in Windows 10. Here's that link.

I had already asked a question in this context a day before (see also for further information).

Is there a tool I can use to modernize the CHM file to make it usable on my machine?

Answer 1

I have never seen a CHM help file that did not work on Windows 10.

The link you mentioned points to an even older help system namely WinHelp with the .hlp file extension.

This help system has not been supported for a long time. Only extensive steps still allowed to open *.hlp WinHelp files some time ago (see https://stackoverflow.com/a/43643026/1981088).

There may be a confusion between WinHelp (.hlp) and HTMLHelp (.chm). To test this, copy your help file into a local directory and double click on it. The file must then be opened and displayed in a help window under Windows 10.

AFAIK - you'll not need a tool to modernize a CHM file for use under Windows 10.

FYI - I remember some old stuff Connecting HTML Help to C++/MFC Programs

Answer 2

When CHM Help Files showing up blank in windows 10.

Do the next:

Find the .chm file location, right click, and go to properties and check "Unblock" and apply