I rarely use WMC on my desktop, but when I do I always get a message saying a CableCard was detected on the network. However, the CableCard is already set up correctly and working perfectly fine in WMC. This is with an HDHomerun Prime. Is there anyway to disable these messages?
You say "perfectly fine"... can you check the Prime LOG and see if it agrees? Look for indications of Activation and Authentification being OK or not. If those are OK then I'd run the Digital Cable Advisor on WMC just to get it into agreement... I'd say something has lost its settings and once restored it should be fine, again, and without those popups!