(imported comment written by cstoneba)
this is what I do to turn off Windows Automatic Updates:
//x86
if {not x64 of operating system}
regset "[HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\WindowsUpdate\Auto Update]" "AUOptions"=dword:00000001
regset "[HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\WindowsUpdate\Auto Update]" "AUState"=dword:00000007
endif
//x64
if {x64 of operating system}
regset "[HKEY_LOCAL_MACHINE\SOFTWARE\Wow6432Node\Microsoft\Windows\CurrentVersion\WindowsUpdate\Auto Update]" "AUOptions"=dword:00000001
regset "[HKEY_LOCAL_MACHINE\SOFTWARE\Wow6432Node\Microsoft\Windows\CurrentVersion\WindowsUpdate\Auto Update]" "AUState"=dword:00000007
endif