Vista - That is a bug in Vista?

Using the command line below to disable or restore auto tuning for network:
netsh int tcp set global autotuninglevel=disable
netsh int tcp set global autotuninglevel=normal

I also found that the registry vaules were changed by the commands above.
HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\Tcpip\Parameters
EnablePMTUBHDetect=255
EnablePMTUDiscovery=255

But i know the two values are boolean type, they are only 1 or 0
Microsoft Corporation

Could you please tell why?
Thank you
Steven

As far as i know, the vista registry has many of the tcp settings present in XP but they are set to FF hex value and revert back to that value if you change them.
The Tcp Window Size in Vista is based purely on AutoTuning being either on or off, and there is no registry entry to use.
So, with regards to the Microsoft TCP/IP Registry Values for Windows Vista and Windows Server 2008, i hope it is a mistake (copy/paste from ex versions) though it's been updated early this year. (for example same difference with TcpUseRFC1122UrgentPointer)

Hi Steven,

We can help you out more if we know what your trying to acomplish?

Cheers
dmex aka Steven too