Thank you again for the responses -
 
Gustabo - That Power Management setting was Disabled when I looked.
 
57 Gregy - Correction to my earlier post: Only the MIDI meters are jumping. No audio tracks are showing any activity on any projects. That seems to indicate something within SONAR to me.
 
Cactus - Sorry - I didn't make a complete accounting of my trouble shooting efforts nor did I post the ones I did post in the proper sequence. Thank you for the clarity. The guitar, guitar cable and interface analog audio all check out. I took the MIDI cable from the interface and ran it between my other PC and its printer & it worked fine. My interface does have a small GUI mixer utility and it appears as expected, except for the same lack of audio. I confirmed all the latest drivers, firmware and tools at the Steinberg website.
All of my track outputs now say "None" and when I click on the output button and open that little menu, I'm not offered any of the former options I'd see to select the interface's outputs
 
 

OK but still the one question. Do you hear your guitar in the headphones? I"m not clear if this interface has direct monitoring as a stand alone unit. I don't see any controls on the front panel.  All my interfaces can monitor the input as stand alone units.  In other words, even with no USB cable plugged in you can hear your input signal and the headphone level can be turned up quite loud.  On my Tascam there is a control for blending the computer output with the inputs. 
My Focusrite this is managed with the GUI but it too will monitor the input even if my computer is not even on. 
 
It sound like there is something either broken or the drivers are not installed right. 

OK - finally a solution.
Dialed up a system restore in Windows and one of the restore points offered was a few days ago and mentioned "C + + 2015" and said "Installed". I"m thinking Windows must have done that in the background when I was online, which is rare. As previously stated, I only go online for CCC updates or the occasional software install.
 
Thanks again everyone for the assist. Much appreciated!