I have encountered a couple of problems in the last two days. The first was that I could not connect to the internet and the diagnostic policy service would not work. I managed to fix the internet connection problem by running the following commands on the command prompt:
net localgroup Administrators /add networkservice
net localgroup Adminsitrators /add localservice
This enabled me to access the internet. However, now I notice that the windows firewall is turned off and I can't turn it back on. I tried running one of Microsoft's fix programs and that's when I noticed the Diagnostic Services were still not running. I tried to turn it on again but the system won't let me. Even as Administrator. Any help to resolve this would be appreciated as I can't find any solution on the net.
Happy to provide specific detail if needed. Not sure what additional details are needed.