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How to prevent Vista's autoupdate

From here. To prevent the annoyance of being bothered to restart the computer or, worse, it deciding to restart itself and killing your batches:
  1. Type cmd in the Start->Search box and run it with Ctrl-Shift-Enter for admin mode.
  2. Type
    net stop "windows update"
    
That's it, and it'll turn itself back on when you restart.