About 15 minutes. Never used to. It does eventually start up OK.
Any ideas?
What have you tried so far?
What operating system are we talking about?
Assuming we are talking about some version of Windows here, what did you
find in the event viewer?
Again assuming some version of Windows, are you connected to a domain,
or were you once and are not any more or are you in a workgroup?
Did any of the results of Googling "preparing network settings" not work
for you? Which (if any) did you try and what was the result?
Based on the information you have given my initial answer to your
problem will have to be as much help as your question was....... I have
no idea.