Invalid MS-DOS function occurs on Microsoft® Windows Vista™

The error Invalid MS-DOS function occurs on Microsoft® Windows Vista™.
Symptom

The Invalid MS-DOS function error occurs when a file is copied on Windows Vista through a dynamic view where the following is true:

• The file is greater than or equal to 256 KB
• The file is under source control
• The file is checked-in.

The error occurs whether you try to copy and paste or drag and drop from ClearCase Explorer or from Windows Explorer.

Note: The error Invalid function occurs if you try to copy from the command-line.

http://support.microsoft.com/kb/941673
To add the CopyFileBufferedSynchronousIo registry entry, follow these steps:

1. Click Start, type regedit in the Start Search box, and then press ENTER.
2. Locate and then click the following registry subkey:
   HKEY_LOCAL_MACHINE\SOFTWARE\Policies\Microsoft\Windows\System
3. On the Edit menu, point to New, and then click DWORD Value.
4. Type CopyFileBufferedSynchronousIo to name the new entry, and then press ENTER.
5. Right-click CopyFileBufferedSynchronousIo, and then click Modify.
6. In the Value data box, type 1, and then click OK.
7. Exit Registry Editor.