I have two xpsp2 systems on the same 10/100 switch, both at 100fdx.  I'm
trying to transfer a single file thats about 5gb in size from one to the
other.
I create a share at the root of the C drive on the machine that has the file.
I map a network drive on the machine that I want to copy the file to using
the IP address, share name and admin account of the serving machine.
Using Explorer I dnd the file from the network drive to the local drive. 
The copy proceeds normally and takes about 45 minutes.  There is plenty of
free space on the destination drive.
With about 20 seconds remaining the copy aborts saying "The network name is
no longer available". However, I can still see and interact with the network
drive mapping to the remote system.  I also have a RDP session going to the
remote machine at the same time, so network connectivity is good.
AU is enabled on both systems and claims to be up to date.
netstat shows the connection is on port 445, so CIFS was negotiated.
I've also tried the same operation from command line, but the error was the
same verifying that it probably comes from the redirector.

This troubleshooting may help,

specified network name is not longer available System error 64 - The specified network name is no longer available. System error 53. The network path was not found. Event ID 3013 - Description: The ...
      www.chicagotech.net/troubleshooting/systemerror64.htm 


Bob Lin, MS-MVP, MCSE & CNE
Networking, Internet, Routing, VPN Troubleshooting on http://www.ChicagoTech.net
How to Setup Windows, Network, VPN & Remote Access on http://www.HowToNetworking.com
  I have two xpsp2 systems on the same 10/100 switch, both at 100fdx.  I'm
  trying to transfer a single file thats about 5gb in size from one to the
  other.
  I create a share at the root of the C drive on the machine that has the file.
  I map a network drive on the machine that I want to copy the file to using
  the IP address, share name and admin account of the serving machine.
  Using Explorer I dnd the file from the network drive to the local drive. 
  The copy proceeds normally and takes about 45 minutes.  There is plenty of
  free space on the destination drive.
  With about 20 seconds remaining the copy aborts saying "The network name is
  no longer available". However, I can still see and interact with the network
  drive mapping to the remote system.  I also have a RDP session going to the
  remote machine at the same time, so network connectivity is good.
  AU is enabled on both systems and claims to be up to date.
  netstat shows the connection is on port 445, so CIFS was negotiated.
  I've also tried the same operation from command line, but the error was the
  same verifying that it probably comes from the redirector.

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