Problem in my notebook

I have problem with my vista. For your info, in my office, we use LAN. At several time i juse handphone as modem for acces internet that not allowed in my LAN. After connect it to internet, a problem occured. The DNS setting of my LAN is lost, and when i try to change it again, a warning appear like above. I cann't automatic update my vista and windows defender with error code 80244019

Plissss help me..............

For your info, i use Vista Basic SP 1,