When you copy data to an autoloader tape drive in Windows Server 2003, performance is slow

When you copy data to an autoloader tape drive in Microsoft Windows Server 2003, performance is slow.

This problem may occur if all the following conditions are true:

• You are using one of the following autoloader tape drives:
  • Dell 120T DDS4
  • Dell 122T VS80
• The computer has an Adaptec 39160 SCSI controller.
• You are using Adaptec driver version 6.4.630.100.

Warning Serious problems might occur if you modify the registry incorrectly by using Registry Editor or by using another method. These problems might require that you reinstall your operating system. Microsoft cannot guarantee that these problems can be solved. Modify the registry at your own risk.

To resolve this problem, add a DWORD value that is named AlwaysDisableMCN to the following registry subkey: To add this registry value, follow these steps:

1. Click Start, click Run, type regedit, and then click OK.
2. Locate and then click the following registry subkey:
   HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Enum\SCSI\Changer ID\GUID\Device Parameters\MediaChangeNotification
3. On the Edit menu, point to New, and then click DWORD Value.
4. Type AlwaysDisableMCN for the name of the DWORD, and then press ENTER.
5. Right-click AlwaysDisableMCN, and then click Modify.
6. In the Value data box, type 00000001, and then click OK.
7. Quit Registry Editor, and then re-start the computer.

Microsoft has confirmed that this is a problem in the Microsoft products that are listed in the "Applies to" section.

The third-party products that this article discusses are manufactured by companies that are independent of Microsoft. Microsoft makes no warranty, implied or otherwise, regarding the performance or reliability of these products.