Just some tips:
a. do not indicate the ip address of the server as much as possible on the screenshots that you are posting.
b. if others will be trying to access your server's ip address, they would be able to gain some of the confidential information if you haven't yet set a password to your admin account.
c. upon logging in, i noticed that the nodes have unknown interfaces. There are several reasons why there are unknown interfaces in your nodes. It might be that the snmp community string is not validated or not the community string configured on the box (possible mismatch). It might also be that the server ip address is not allowed to gather snmp queries to the equipments you are monitoring, you might need to check on the access-lists or firewall on the device. It might also be that the equipment is not yet supported (but this is the least reason). It might also be that your server is not able to monitor more elements, I have seen that you have been using a windows xp as your demo server. You might want to try this using a windows server 2003 since v9.5 consumes a huge amount of resources in the server.
d. How did you know that the NPM suddenly stop updating? You may want to check if the Solarwinds Network Performance Monitor is running. You may do this by going to Start> All Programs> Solarwinds Orion> Advanced Features> Orion Service Manager. Be sure that all services are "Running". This might also be the reason why you are having unknown interfaces on the equipments you are monitoring in the web.
>>>it seems that the polling engine is down.
To summarize, don't forget to secure your solarwinds access and should you have questions in implementing solarwinds, you may contact the engineer or sales of solarwinds to answer your other querries. They will be willing to assist you to give you reasons on why you should purchase solarwinds.
I'm not from the Solarwinds Technical Support that is why my answers may not be correct for others or they may have other ways to resolve your issue. Things I have mentioned here where just based from my previous installations of solarwinds. To be exact 15 big companies here in our country are already using Solarwinds in network monitoring.
I hope I answered your questions.
There are some cases that when you restarted a server, the solarwinds network performance monitor service will still remain on a "shutdown" state not unless you started it again. Please check this.
Are you using SQL Express as the database? Do you have any other modules installed besides NPM?
i think he's also using NTA.