]nvda] CHM, a.k.a. Microsoft Help files

Chris Mullins

Hi Tonea

I’ve just re-sent this as the original had incorrect information regarding moveing the mouse pointer and activating buttons using NVDA.  Note also the alt+o and alt+s commands referenced are Windows commands not NVDA.


I found a chm file on my machine and opened it.  On entry, I was placed in the Contents list and used arrow keys to traverse it.  When I found a topic I wanted help on I pressed f6.  This moved me to the help topic details.  I used arrow keys to move around the help topic window. From here I switched into screen review mode and located the following gbuttons

Hide Print Options Search Contents Favorites       


I could access these buttons via review cursor then use NVDA +Numpad / to  move the mouse pointer , then activated button using numpad / to simulate a mouse click.  I also found that alt+o opens a context menu containing the following:

Hide Tabs






Internet Options...



Some of these are probably equivalent to the header items you  could not access.  Alt+s also opened up the search function which was also accessible.




From: nvda@....] On Behalf Of tonea.ctr.morrow@...
Sent: 17 January 2018 15:05
To: nvda@nvda.groups.io
Subject: [nvda] CHM, a.k.a. Microsoft Help files


A while back, I asked for help with making my documentation equal access to NVDA users. James Austin And Cearbhall O’Meadhra both answered my call and have been very patient in helping me.


Microsoft help files end in a CHM extension. Just a refresher: this format generates a window with the following buttons along the top: Hide, Back, Forward, Home, Print, and Options. Below the button bar, there is a left-hand side that contains three tabs: Content, Search, and Favorites. In the Contents tab, there is an organizational tree that allows you to look at the page names and navigate directly to the page you want. On the right hand side, there is the content window. It displays the header of the page and any navigation buttons relating to the page, such as Previous, Top, and Next. Below the header is the content for the page.


On the first run through, the content window was blank. I contacted my software’s maker and they had me make some changes. I’m not using Word, but just as Word can save as a single document or PDF or web page, this software can save as an entire web site, a CHM help file, or a PDF. I had applied something they call a skin to give the entire set of pages the same look and feel as the software it is supporting. These guys told me to remove the skin. According to them, all that would remain is Microsoft’s CHM frame and my pages within it.


On the second run through, the content window was there, but the content header (with the buttons that appear next to it) was not visible to NVDA. This told me that most of the problem was in the skin. I contacted the software maker since the skin was from one of their templates.


I’m quoting their response: The most likely cause there is a non-scrolling header, where the topic header stays in the same place and the topic content scrolls in a box below it. If the screen reader is old/poorly programmed/dumb then it is quite possible that it wouldn't be able to handle that. End quote.


Well, on behalf of everyone here, I was offended. I may not yet have access to NVDA but I know everyone here works hard to help it be a really good product. I’ve gone back to my files and, as a sighted user, I can’t see any header that stays in the same place. I will be contacting them about that and pushing them to nail down this problem and also to help me get a skin that doesn’t make the files invisible to screen readers.


However, I also have to be respectful and ask if anyone knows of a CHM file that is completely readable to NVDA? Is any of this problem an issue with the NVDA software? Or, is it a known problem with CHM that users of other screen readers also experience?


Thank you for your understanding,


Tonea Morrow

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