Go in this order: each step rules out a cause and tells you where to look.
1. Is the service active?
In the panel, open your service. If it shows as suspended, it is almost always an unpaid invoice: services are suspended the day after the due date. Once you pay it, it reactivates by itself (more in renewal and deadlines).
2. Is it powered on?
The Overview tab shows the status and graphs. If it is off, click Start. If it is on but does not respond at all, try Restart and, only if it hangs, Force power off then Start (what each button does).
3. Look at the screen with the VNC console
The VNC tab shows the server's screen even with no network (how to use it). There you will see whether:
- Windows is installing updates: wait for it to finish, it can take a while.
- It is stuck at boot or showing an error.
- Everything looks normal: then the problem is network or firewall (read on).
4. Did you lock yourself out?
More common than it seems:
- Enabling
ufwwithout allowing SSH first (ufw allow 22/tcp). - Changing the remote desktop or SSH port and connecting to the old one.
- A Windows firewall rule or a Security tab filter blocking your own access.
From the VNC console you can log in and undo the change, because it does not depend on the network.
5. Is it full?
In the Overview graphs: CPU at 100% all the time, memory exhausted or a full disk leave the server unresponsive. See your VPS's usage.
6. Is it something general?
Check the service status for an incident or maintenance at your location.
7. If none of the above
Open a ticket with what you saw at each step: the status in the panel, what the VNC console shows and, if the server is on but the connection does not get through, an MTR from your computer.