If you're a command-line type of user, you could try the following commands:
- ipconfig /flushdns
- nslookup
Then, under this, you will get a > prompt. First, enter the command:
server
It will tell you who is your current DNS server. If this is something like 192.168.1.1 or similar, this is likely your own router. Try entering:
server
Retry to see whether this makes a difference. You can also try:
server 208.67.222.222
This is for OpenDNS. It should also be able to resolve your server IP address.
If this works, this indeed means that your domain and web site are properly registered on the net and are properly resolving for everyone. If not, contact your provider so that this gets resolved.
You then may have to flush the DNS cache of your router, if needed.
All this assumes that your website/server is hosted somewhere that is known and is setup by your provider. Usually, your web site provider is also the domain hosting provider. For myself, I use GoDaddy, and both my domains and web sites are hosted there. However, i have full control over all my domain and zone files. Your provider shouyld also be able to help you for any hosting matter.