A couple of weeks ago there was a lengthy power outage in the area where my server is located which drained the UPS battery and shut down the server. When the power came back up, I re-started the server which booted fine but didn't find the on board NICs so had no network services and was consequently useless. It also, somewhat strangely, showed that there was only three days left to activate the operating system despite it being in use for over three years!
After much tinkering and several re-boots, I did get the NICs showing up again in device manager and all of the services running.
Everything has been O.K. for two weeks but on Saturday I decided to replace the UPS as the old one was showing signs of a failing battery. I shut down the system normally, replaced the UPS, but when I started the server I had the lost NICs and false activation notice problem all over again. As before, after much tinkering and re-booting, I did get everything back up again but I need to figure out what is causing this. The false activation alert seems to indicate that this is a software issue.
Hopefully, someone may have experienced this and rectified the problem.