If you did reboot your machine check to make sure The WMC and RPC Services are set to at least manual, and Automatic or Automatic (Delayed Start) and running. How to: Services - Start or Disable
You can force a service to start by right clicking on it and selecting properties then go to Option One, step #6.
Here are how mine are set.
Windows Media Center Services (WMC):
Remote Procedures Call (RPC):
You can if you want to, set all five to automatic, make sure you reboot after adjusting settings.