Questions asking us for a download source shpuld be considered off-topic, but on a case-by-case analysis, they may still be fairly salveageable.
Regardless of policy, I see some issues with these sort of questions.
The user is asking for a web link
If we assume the download is accessible, it seems to me like good answers would follow the following format:
You can download X from the (X/Company Y) website. Just follow this link for the download page.
It seems as if it would be rather difficult to post a good answer, with out providing the link. This creates a Catch-22; it can not be considered a good answer if it does not hold with out the link. We have a very strict policy with this, to prevent good answers becoming bad answers due to link rot.
To a minor extent, the user is asking for recommendation
We consider software and technology recommendation questions off-topic. I would only loosely group these questions in with "where can I download X?", but ultimately, the user is asking us to recommend a specific website to provide the appropriate technology.
One might argue that different answers may also lead to different 'preferred versions'. While this is an issue I can see, I am not sure it is really a big one.
Salvage versus Close
It is entirely possible that we could edit these questions to be on-topic, and still draw the response the user is looking for.
Why is X no longer accessible?
Sometimes, the root of the question comes from confusion, when a previously accessible piece of software becomes impossible to find.
In the example, the user likely1 googled "Havok" and found that although there is a lot of reference to a shareware version, there are no links on the official page.
As answers have since pointed out, a semi-recent acquisition resulted in the shareware version being discontinued. Bummer.
I see no reason we can not allow "Why can't I access X anymore?" questions, in the rare situation where this is the actual case. I actually found the answers, in this case, very helpful.
Is X available to the public?
When it comes down to a complete lack of being able to find reference to a download, I see no reason why the user can not ask if there is a download.
This might highlight the actual problem, as there was with the example question. A good answer would still provide links to the download, if valid, while still directly answering the question in text format. Win, win.
1 Assuming, in good faith, that the user did try to find the download, themselves, before posting.