1. What is the d:-drive? A hard disk partition, a cd-rom or a mapped network drive?
2. If you doubleclick Windows should execute the command that's shown bold when you right click. What's that command?
3. You write "some of my PC". Does that mean that this same problem occurs on multiple machines? How many? Suddenly? All started at the same time?
4. What changed since it last worked?
5. "No network present or available" (with quotes) gives no hits in google. That makes me suspect that that isn't the exact literary text of the error message. Can you give that, or tell more?

Kees