The iPhone “Fantastic4” cannot be restored at this time

Hi TechyV Guys,
I tried to update iOS 5 and received an error message. It is indicating something non-availability of the update server.
However, after sometime I tried and received the same error message.
I do not know the reason behind it.
Please help me to solve this issue.

The iPhone “Fantastic4” cannot be restored at this time because the iPhone software update server could not be contacted or is temporarily unavailable.
Please try again later.
