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Now a network timeout can be caused by a number of issues
1) Your firewall could be knocking out the connection
2) Your antivirus could have a built in firewall that knocks the connection out
3) If you are using a wireless connection for your computer please plug into your router directly and try again
Try disabling your firewall or your antivirus while your computer is downloading the update then turn it back on after it is downloaded.
If you don't know how to check please let me know the type of virus protection software loaded on your computer and I will walk you through the steps