Not released, just tagged. Release will take in a few weeks.
If you are champing at the bit, the latest nightly is as close as you can get for now, download the 30 June build from http://downloads.kicad.org/windows/nightly/. To install, just run the exe.
If releasing rc3 takes weeks then v5 will be out before there is a package for rc3 
I suspect the operating systems that get a package for rc3 will have it within a few days.
There hasnât been an rc1 or rc2 package for WindowsâŚwhich was the question.
That wonât likely happen unless someone, like you, writes it.
I can tell you that for a very recent nightly, with a clean install (as if KiCad was never on the machine), ensure that all the options are checked (except maybe the help files). Then agree to all the default prompts.
Using a recent RC2 nightly would be my recommendation; standard âusing the nightlies disclaimerâ applies. The reality is that when more users start to transition to V5 more bugs may be found; but this situation is also likely to happen when the official âstableâ is released.
Even though there is not great documentation at this time, most things are more intuitive than they have been in the past. If you can not find a solution you can always post your question here on this forum.
I have to disagree. Do yourself a favor and let âEnvironment variablesâ be unchecked. It would only create problems later.
I have not personally experienced any problems with a KiCad instal on a machine that never (knew it) had KiCad installed on it.
@Sprig was very specifically writing about a clean install. Until a few days ago a clean Windows install without those variables set pointed at non-existent directories.
I agree with you that for all existing users, donât set them.
Iâm talking about clean installs, too. When you possibly want to install another next version later alongside 5.0 they will again create the same problems as they do now for v4/v5.
That was a bug fixed a few days ago, so is now bad advice. [June 27 in fact]. Better to leave âset environment variablesâ unchecked on Windows installs.
I would not advise a new user to install multiple versions.
V6 is years away, so not much of a problem
A couple of years ago v5 was years away and v4->v5 wasnât a problem. Now it is. Those who are now new users will be old users when 6.0 will be released and have forgotten the environment variables which they set couple of years ago and will come here for advice because they have problems with environment variables set by 5.0. Therefore, just donât set them. Let the KiCadâs own automatics set them as internal variables and edit them with the KiCad UI if needed. It works perfectly (after the bugfix, for typical default installtions) and is actually easier and more simple than using system environment variables.
âThose who cannot remember the past are condemned to repeat it.â 
In two years time, the stable version will have stepped several times from 5.0.0, so plenty of opportunity to fine tune the environment variable behaviour.
Right now the bigger headache will be new users who donât even know what an E.V. is.
Hopefully someone will be inspired to extend the configuration tool for saving, exporting and importing these settings, once the V5 release panic is over. I donât think that this would have to wait for V6
What configuration tool are you referring to?
RC3 tagged!
https://lists.launchpad.net/kicad-developers/msg36380.html
Does anyone know if the 01JUL18 nightly is the RC3?
Yes, the build r10601 is the first (and only, for now) rc3.
R10601 (RC3) binaries for Windows can be found here (in case somebody doesnât know):
http://downloads.kicad.org/windows/nightly/
In the dev mailing list Wayne told that 20th this month is the target date for tagging 5.0.0. But it depends on the bug situation. https://lists.launchpad.net/kicad-developers/msg36455.html
Edit: the ârelease dateâ could be 27th.