NETSH int ip reset on vista ultimate

Hi,
I try command "netsh int ip reset" on Vista ultimate
This one does not seem to give correctly as a customer DHCP. (as on XP)
The informations of IP address disappear well but the box "To use
following IP address" remains notched + that does not erase Addresses
DNS fixed manually. This-entraine a Connectivity limited to Reboot.
I specify that I am on an official version Vista Ultimate , in admin mode ,
invites it DOS started in admin mode, Windows Update OK , active UAC
or not => same error ....
Examples of Command tested = > give the same thing
c:\windows\system32 \ >netsh int ip reset c:\trace.txt
c:\windows\system32 \ > netsh int ip reset

Foot-note: I have a message "Failure of Réinitalisation de Requete of
echo, access refused" then various Réinit OK.
Do you note the same thing?
Did syntax change?
Thank you for your assistance.