Error 404 message

You need to provide some more context.

Does https://localhost work?
Do any other subdirectories of https://localhost work?

When I press https://localhost I get this message
“Welcome to XAMPP for Windows Version 1.6.1 !

Congratulations:
You have successfully installed XAMPP on this system!
Now you can start using Apache and Co. You should first try ?Status? on the left navigation to make sure everything works fine.

For OpenSSL support please use the test certificate with https://127.0.0.1 or https://localhost

And most importantly, a big thanks for help and support to Carsten, Nemesis, KriS, Boppy, Pc-Dummy and all other friends of XAMPP!

Good luck, Kay Vogelgesang + Kai ‘Oswald’ Seidler”

But when I press https://localhost/Joomla/ I get 404 message.

I don’t know why that is — but I think there’s a better way to do it anyway — to set up a Virtual Host for each project.

This explanation looks good: https://sawmac.com/xampp/virtualhosts/

The only thing I didn’t see him mention, is that you need to make sure that in the main Apache config file, httpdd.conf, you need to make sure that the include of httpd-vhosts.conf is not commented out. (I think it is, by default).

Here’s another post: https://www.tildemark.com/setting-up-virtual-hosts-with-xampp-running-on-windows-xp/

What I do, is I have a completely standard format that uses a .local extension for my local sites. So if my customer’s site is mydomain.com, I will setup mydomain.local on my local site. You can “fool” your local site to think any domain is local, and then you have a cleaner way of working, IMHO.

This way, it’s a very simple copy-and-paste operation to set up new virtual hosts, once I have set up the first one.