This is vital for accessibility tools, like screen readers for blind people. Also for as-you-type word prediction tools, autocorrection that works globally.
More generally power like this lets you turn Windows machines into A Thing That Does Just What You Want, rather than a locked-down thing like an iPad. Which are also great, but a different use case. For example, you could use this for exam proctoring, or kiosks, or remapping Windows keys to particular functions in your video game or Android emulator.
Img tag was important, but it doesn't mean that web was text only before the tag was introduced: people were linking to pictures in the same way how would one link to any other resource, and when you opened the link, the picture was shown in a new window.
You can use WiX Toolset version 4 to create Windows installers. Version 3 is Windows-only, but Version 4 runs under .NET "the-one-that-runs-on-Linux". It produces MSI files.
It's a very good plan. We would have lower pollution, fewer deaths, higher living density, lower carbon emissions. It is, however, very unusual and unpopular.
Most important question: what does your friend want to do that he can't? You're describing his limitations, not his goals. Does he want to read, but not write? A Kindle might be better than an iPad - longer battery life. Does he want to read, but not have to raise his arm to do the page turn? Then back to iPad but using a switch device that can be operated from one finger.
I'm not explaining this well, because I'm a technologist, not a therapist: in the UK the role would be "Occupational Therapist". However, in my experience, they are focused on improvement and the regaining of function: only when this avenue is exhausted will they begin to look at assistive technology. But I am probably being unfair.
Sorry, it's late, and I am a n00b. You wrote email and editing.
Your friend's problems are largely about control and typing. They may be able to use one arm, but it may tire fast. Consider alternative mice, including trackballs. A keyboard if possible, perhaps a tablet with keyguards. If not, some kind of switch control for an onscreen keyboard: it will be slow but maybe more useful. One Switch Mouse, above. Built-in features, like Windows here:
https://support.microsoft.com/en-gb/help/27936/windows-10-ma...
Eyegaze: cameras that track where you are looking. Hard to use, probably not best if your friend can use an arm.
Speech recognition: you really want Dragon Professional on Windows. If you can't get a trial of that, macOS speech recognition. You MUST MUST MUST have a decent mic. Windows 10 machine, try Windows Key + H in an edit box, or this freeware (my employer again):
https://www.clarosoftware.com/login/admin/labs/#clarodrake
Your friend is still regaining function, which changes the dynamic: using the built-in features, maybe with a trackball, might be best until you know where they end up. Again, this is an OT call.
