Comments

This is a "clear pass" standard piece of work, David - well done!
TMA 02 covered a lot of ground, & I'm pleased that you've shown good understanding across the range of activities you had to carry out.

I have devoted the largest part of my feedback (on everyone's TMAs) to Q1, the plan. This is partly because all the major questions you'll have to answer from now on (in the ECA too) involve writing a plan, so tips you pick up here will help you to higher marks in the future. Also, going wrong at the planning stage can mean your whole report is less effective than it might have been, so it's worth checking that you fully understand how a title, a plan & a report relate to each other.

I've enclosed a file called "plan.htm" which shows the kind of plan that would earn a high mark.

Q1
If this is your first ever academic report plan, it's a pretty good attempt!

Introduction:  Clear, straightforward & to the point - well done!

Main body: It will be best to select three OSs to cover in detail, & your plan should indicate how you are going to answer the "why" part - you've merged this with the "overall significance", whereas it needed to be examined separately. Your handling of overall significance is fine (the term "commoditisation" could perhaps be mentioned).

Conclusion: This is fine (no penalty for the odd bits of dodgy English, but keep an eye on them).

References: These are fine, too.

This was a useful practice - I think your next plan will be even better :-)

Q2
This is a good start. It covers a good range of factors & explains them clearly. Each would need more development, though, to earn higher marks (when you've only used around 2/3 of the word limit,  the chances are you won't have covered the topics in sufficient detail for top marks).
You could, for instance have explored the way success led to success, as Microsoft's marketing campaigns ensured large numbers of consumers upgraded or converted to subsequent versions of Windows.
You do well to provide the sources on which your summary is based. A few quotations from those sources would have livened up your summary a little.

Q3

These are thoughtful points, which you've explained well enough for a pass mark.
Your first advantage is clearly based on Dewar's paper, and makes some reference to your own experience (though not very extensively). The second advantage, unfortunately, is not about conferencing at all, & the way it can be used to support online learning. With the disadvantages, your answer is more consistent, but only the first one is taken from Dewar's list, & neither mentions your personal experience of computer conferencing on T171. There was room to extend your answers in this direction, as you've only used around 400 of the 500 words available to you.