This happened to me the first day i bought my new laptop. I have Vista Home
Premium and i had set it all up connecting it to the internet. As soon as the
connection had established it straight away started installing updates. After
they had finished it prompted me to restart so i did. After logging back on
again the internet wouldn't connect. So the only way was to do a system
restore which brought the connection back. I then later found out the the
software licensing service had stopped working, meaning it was telling
windows i didn't have a genuine copy of windows. This might not be the
problem with ures but it fixed mine. So access the services click start - run
- type services.msc and scroll down to Software Licensing Service. If it
hasn't started click start it it is unable to then you have further problems
and need to contact microsoft. If it does start then double click it and set
it to automatic.
Hope this helps
and good luck