UAG Certificate Enrollment Error, Logon Failure.

Hi All,

I have been configuring UAG with the help of TLG provided online. On one machine I have to enroll IP-HTTPS listener certificate. For that i have followed following steps.

Run > mmc > files > Add/Remove snap-in > certificate

on the new window I select computer account then next

then Local Computer Then Finish.

Now, Right Click on the details Pane All Tasks > Request New Certificate > AD Enrollment policy

Now After Clicking Next I am getting Error 

Enrollment Error

Logon Failure : Unkown Username or Bad Password.

Recently I have change only this system's password (System Name UAG2SERVER)

Can anyone please help.