Slow file copy or slow file transfer with various Windows versions 2k8, 2k8R2, 2k3

There are various posts in the Microsoft Technet File Systems and Storage forum (and other forums) indicating slow file copy/transfer speed. The details vary, but most of them involve either Windows Server 2008, Windows Server 2008 R2, or Windows Server 2003. This document is an attempt to coalesce all the various solutions into a single place. Note that the author of this document has not personally tested any of the solutions, but various posts in the forum indicate these to have solved the problem for some users.

Symptom: File copy or File transfer speed is slow, either to a local drive or a network drive, especially so when a Windows Server 2008 or newer Windows file server is involved.

Possible Solutions in no particular Order

  • Make sure both IPv6 and IPv4 are running on 2008 R2, even if the 2008 R2 server is the lone IPv6 device on the network! There may be alternate solutions but this solution has been reported to work [1] [2]
  • Tune TCP on client – set autotuning to off “netsh interface tcp set global autotuninglevel=disabled” [2]
  • Tune TCP on client and server – turn off receive side scaling “netsh interface tcp set global rss=disabled” [3]
  • Tune TCP disable large send offload [5] [17]
  • Tune TCP disable large receive offload [11]
  • Tune TCP – disable  offload [5] [7][9] [11] [16]

Edit the registry key Edit the registry key HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\Tcpip\Parameters; create a new DWORD value named DisableTaskOffload and set its value to 1

  • Use non-cached writes while copying the file e.g. run Windows 7 xcopy which supports a new /J switch to do non-cached writes. The Microsoft Performance Team uses the Microsoft Exchange utility eseutil to copy files using non-cached writes. However, some Microsoft customers may not have Microsoft Exchange. Also, the legalities of copying files from a Microsoft Exchange server to a File Server as the Microsoft Performance Team blog in Reference [6] suggests are beyond the scope of this compilation of solutions. [6] [14]
  • Install all hotfixes from Microsoft [8]
  • Don’t use File Explorer to do copy/paste – and if you do, ensure Remote Differential Copy is turned off [4]
  • If one of the drives involved in the file copy is an external USB drive, ensure that you are using the USB 2 protocol and not the older slower USB 1. Start Device Manager, find USB Controller, clock USB2 Enhanced Controller Host, and right click properties; make sure it is enabled. Repeat these steps for all USB2 Enhanced controller hosts.
  • Make sure drive compression is turned off [10]
  • Make sure antivirus is fully updated or if possible, remove antivirus solutions from the equation to see if that is the cause [12]
  • Install all updated drivers from vendors especially NIC vendors and RAID drivers [13] [16]


  1. What causes Windows 2008 R2 slow file and folder copy
  2. Server 2008 R2 core slow file copy
  3. Windows 2008 R2 File and Folder Copy very slow over 1000MBs link
  4. Why is Windows 7 still as slow as Vista with File Copy
  5. Slow network file copy on Windows 7
  6. Slow large file copy issues  Microsoft Performance team blog
  7. Slow file copy between Vista and Small Biz Server 
  8. Low performance when you transfer files from external IEEE 1394 device to server
  9. Very slow DFSR on Windows Server 2008
  10. Server 2008 File transfer is slow
  11. File Copy very slow to Windows Server 2008 R2
  12. IPS driver causes network slowdown
  13. Network transfers start fast then slow down
  14. Windows 2008 R2 large file copy uses all available memory and slows down  
  15. Slow LAN transfer Windows Server 2008 R2 – enable IPv6
  16. Windows Server 2008 R2 file/folder copy/paste very slow 
  17. Windows 7 Large File copy painfully slow 


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