I was trying to disable auto-tuning on a 64 bit version of Windows Server 2008 R2 but was encountered an issue.
The netsh int tcp set global autotuninglevel=disabled command returned Set global command failed on IPv4 The parameter is incorrect.
The netsh int tcp show global showed that the TCP parameters differ between IPv4 and IPv6.
It turned out that the netsh.exe in the C:\Windows\SysWOW64 which is the 32 bit version was being used instead of the 64 bit version netsh.exe which resides in the C:\Windows\System32 folder.
I ran the netsh command in the C:\Windows\System32 folder and it completed successfully.
I have yet figure out why the 32 bit version was used by default but seems like it may be something got to do with the file system redirection. For the time being, I will use the workaround.