How to disable or enable the automatic updates permanently

Click "Automatic Updates"
Ensure it's set to "Turn Off Automatic Updates"
Click OK
Now Click Start->Run
Type "services.msc", press enter.
Find the "Automatic Updates" item(service)
Right click it->Click Properties
Change the "Startup Type" Dropdown to "Disabled"
(This next bit is optional but i did it aswell)
Find the "Background Intelligent Transfer Service"//"BITS"
Right click it->Click Properties
Change the "Startup Type" Dropdown to "Manual"
(Manual because i couldn't work out what else was using BITS[other that Automatic updates], and if there is something that depends on the service it can still be started just by starting the service)

Anyway, then if you want to update you simply change both to "manual" and start them then update.

Or

Use Registry Editor, and follow these steps:
Click Start, click Run, and then type regedit in the Open box.
Locate and then click the following key in the registry:
HKEY_LOCAL_MACHINE\SOFTWARE\Policies\Microsoft\Windows\WindowsUpdate\AU
Add any one of the following settings:
Value name: NoAutoUpdate
Value data: 0 or 1
0: Automatic Updates is enabled (default).
1: Automatic Updates is disabled.
Registry Value Type: Reg_DWORD
Value name: AUOptions
Value data: 1 to 4
1: Keep my computer up to date has been disabled in Automatic Updates.
2: Notify of download and installation.
3: Automatically download and notify of installation.
4: Automatically download and scheduled installation.
Registry Value Type: Reg_DWORD
Value name: ScheduledInstallDay
Value data: 0 to 7
0: Every day.
1 through 7: The days of the week from Sunday (1) to Saturday (7).
Registry Value Type: Reg_DWORD
Value name: ScheduledInstallTime
Value data: n, where n equals the time of day in a 24-hour format (0-23).
Registry Value Type: Reg_DWORD
Value name: UseWUServer
Value data: Set this value to 1 to configure Automatic Updates to use a server that is running Software Update Services instead of Windows Update.
Registry Value Type: Reg_DWORD
Value name: RescheduleWaitTime
Value data: m, where m equals the time to wait between the time Automatic Updates starts and the time it begins installations where the scheduled times have passed. The time is set in minutes from 1 to 60, representing 1 minute to 60 minutes)
Registry Value Type: Reg_DWORD

Note This setting only affects client behavior after the clients have updated to the SUS SP1 client version or later.
Value name: NoAutoRebootWithLoggedOnUsers
Value data: Reg_DWORD: 0 (false) or 1 (true). If set to 1, Automatic Updates does not automatically restart a computer while users are logged on.
Registry Value Type: Reg_DWORD

Note This setting affects client behavior after the clients have updated to the SUS SP1 client version or later.