This article is intended for people who cannot access Euphony machine over a network or have problems with Euphony being able to access the internet.

First you need to check if your hardware is supported. Please refer to this article: Unsupported hardware

It would be good if you can attach the monitor to the machine and see what happens during and after boot.
If EUPHONY in ASCII art letters is not present on monitor screen (even after 10 minutes - enough time for formatting data partition) it means Euphony was not able to acquire any IP address and you will be unable to continue (probably due to unsupported network card) - the rest of the article is not relevant in that case.

There are several ways to access Euphony:

1) Native Android and iOS applications rely on the Euphony machine being able to report its local IP address to our online server
2) Launch Euphony page:  https://euphony-audio.com/launch-euphony/ (relies on the same mechanism as above native applications)
3) Enter this address: http://euphony or http://euphony.local in your Internet Browser
4) Enter this address: http://<euphony-ip-address> in your Internet Browser

For the method 4 you can find Euphony's IP address in 2 ways:
a) Find the Euphony IP address in your router's 'Connected devices' list
b) Connect the monitor to the Euphony machine and make sure there are big ASCII art letters spelling EUPHONY on top and note which IP address is reported below.

Euphony machine upon startup expects to get IP address from the network's DHCP server (usually your router).

Sometimes, due to some yet undetermined compatibility issue between Euphony and the router, Euphony does not get IP address from DHCP server. In this case, Euphony will use static IP addresses: 192.168.1.237 for its own address and 192.168.1.1 for router/gateway address.

If your Euphony machine is behind a switch, you can try connecting it directly to the router and see if that helps (it sometimes does, especially if you have a managed Cisco switch that often causes such problems).

If your subnetwork is not in the 192.168.1.x range but in some other range, let's say 192.168.5.x (this is usually defined by router) then, depending on your router ability to access computers outside its defined subnetwork, you may have two kinds of problems.

1) You can access Euphony machine and its web interface by using method 4 with http://192.168.1.237 (other methods will not work) but Euphony reports problems about not being able to access some online addresses: you are unable to fully register and/or you cannot access online music services like TIDAL or Qobuz.

Note that it is entirely possible that you have the perfect internet connection on your other devices but Euphony itself cannot access the internet.
This happens because although your router is able to access computers outside its subnetwork, Euphony itself doesn't know the correct gateway address (default is 192.168.1.1 when DHCP fails) so cannot access anything on its own accord.

2) You are entirely unable to access Euphony via any of the methods listed above, even by using its IP address. This happens because you have a router that doesn't want to see anything outside of its defined subnetwork.

In the first case, the easy solution is to go to Settings - > System and change Fallback addresses so they match your subnetwork. If your subnetwork is 192.168.5.x then change the fallback address to 192.168.5.237 for the IP address field and 192.168.5.1 for its Gateway field (make sure in router settings that 192.168.5.1 is indeed its address)

In the second case you have a harder problem since you cannot even access Euphony to make necessary changes.

If you are comfortable with the network setup, there is a way to temporarily access Euphony to make these changes and revert back to the original setup.
There are a couple of options but both require some familiarity with network setup, both locally on your desktop machine and on the router. If you don't know what you are doing you can mess up your network (not irreparably but you may be stuck for a time until you figure it out).

One option is to add another IP address to your default network adapter on your Windows machine. This is possible if you have a static IP set up (it probably won't work if DHCP is set up so you may need to assign a static IP address for your desktop machine first). The IP address should be on the 192.168.1.0 subnetwork: let's say 192.168.1.100. This may enable you to access the Euphony machine. Once you change the Euphony fallback address to match your subnetwork, you can remove this additional IP address (and revert to DHCP if you have used it before)

Another option is to temporarily change your router subnetwork to 192.168.1.x. The steps would be:
1) Access router web interface and change router subnetwork to 192.168.1.x and router IP address to 192.168.1.1 (write down original values)
2) The computer you used to do that will probably lose its connection to the router and the rest of the network (as any other connected devices on the same network) so if you use DHCP you need to repair/restart network and if you have static IP addresses you need to change them to match new network (write down original settings) and click Apply.
3) Access Euphony and change Euphony fallback addresses to 192.168.5.237 and 192.168.5.1 (or whatever your default subnetwork is)
4) Change router subnetwork and IP address to original values.
5) You may again lose access from the computer you are using to make these changes so you need to change everything to the original settings (or repair/restart network).

If you are intent on keeping the Euphony machine connected through a switch (i.e., the router is too far) and your switch has its own subnetwork, you need to adjust Euphony fallback addresses to that subnetwork.

Again, if you are not comfortable doing this yourself, try asking a friend who is more network savvy to help you. While it may sound complicated, all this is fairly simple to do (at least for simple home networks with one router) for anyone familiar with network setup.

In any case, you only need to do it once. Even if your router always refuses to issue DHCP addresses to the Euphony machine, once Euphony's fallback static IP addresses are on the same subnetwork everything will work as it is supposed to.