Hi, I have reset my HomeAssistant and now it seems dead. Have I destroyed it or can I reinstall the operating system.
Yes!
Probably both. Possibly neither.
A little more information please. What did you do, what did you do it to, what happened, and what did you try to fix it?
Any logs (formatted in </> forum format) would assist in troubleshooting.
I was unable to login, so I used the reset button on back I thought that would remove the password. Now I cannot find it on network using local or web.
Go easy on me I am 79 years old
Terry
Read thru this and help us a bit. Tell us about your system hardware and install method.
The average age of people helping here is likely over 60, so don’t sell yourself short.
OK Sorry, I just purchased the green home assistant from England, it arrived yesterday in Australia. Could you point me in the right direction for a solution.
Thank you
Terry
Start by connecting a monitor to the HDMI port of the green.
It will tell you and us if it is running or if there are errors or no life at all.
The normal screen should be one telling you to connect through the network and it will then list some IP-addreses and maybe also some hostnames.
I see the problem: You need to turn it upside down! 
Seriously, you should be able to pull it up by its bootlaces back to a working system. It is most likely your hardware is not broken, and the software can be reloaded by following the recovery documentation.
First things priority: The green will need an internet connection to download software from the internet. Check this is working correctly. From your router you should be able to find the IP Address the green is allocated. If needs be, watch when you power on your green and see if a new connection is allocated an IP Address on the router.
I strongly recommend you lock that address in to make it a Static IP Address in your router DHCP configuration screen. You can then reliably and consistently come back to that address when troubleshooting instead of guessing and hoping. A lot of potential pitfalls can be avoided by doing this allocation at your earliest point.
Did you attempt this method to find your password?
If not, this procedure should get things going again.
The key is patience, especially if everything has to be downloaded again and you don’t have a fast internet connection. Leave it for a few hours can often be the key to a successful recovery.
If you had it configured and running well, you should be able to restore from a recent backup so don’t wipe it. If you were in the initial process of setting it up, maybe starting afresh might be a viable option.
If you get stuck, yell. We’re not that far away. Keep us posted on progress too.