Why Microsoft Windows Update options are grayed out?

Problem Description: When user clicks on Windows Update in Windows XP machine all the options in Windows Update are Grayed out.

Cause: This issue can be caused due to different reasons.
Scenario 1. The machine you have is/was a SUS controlled machine.
Scenario 2. Due to Group Policy these options are blocked
Scenario 3. User do not have enough Administrative privilages to make changes.

Resolution:

Scenario 1: The machine you have is/was a SUS controlled machine.
In such scenario First of all we need to determine if the machine is SUS configured. Following is the method to find it:
>Click 'Start' Menu
>>Click 'Run'
>>>Type 'Regedit' and click 'Ok'
>>>>In Registory Editor Navigate to HKEY_LOCAL_MACHINE\Software\Policies\Microsoft\Windows\WindowsUpdate
>>>>>In the right side of the pane look for WUServer and WUStatusServer entries. These entries usually carry the HTTP name of SUS Statistics server (http://SUSServerName)
>>>>>>If you find those variable then easy fix is to export WindowsUpdate registry hive and delete it. Now your machine will not be controlled by SUS any more and you should be able to configure options as you like. If absence of this registry hive User Configurations takes affect.

Scenario 2: Due to Group Policy these options are blocked
In a scenario where these options could be blocked due to Group Policies we can use the folliwing method:

>Click 'Start' Menu
>>Click 'Run'
>>>Type 'gpedit.msc' and click 'Ok'
>>>>Nevigate to 'ComputerConfiguration\Administrative Templates\Windows Components\Windows Update' and make sure that all the settings are set to 'Not Configured'
>>>>>Nevigate to 'User Configuration\Adminitrative Templates\Windows Components\Windows Update' and make sure that all the settings are set to 'Not Configured'

***SPECIAL NOTE****
Change in policy values and of the day is affecting the same registry hive we have discussed above.

Scenario 3: User do not have enough Administrative privilages to make changes.
In this scenario all we need to do is to make the user member of local Administrator group. This can be done 'Computer Manegement' consol or 'Users Accounts' consol from Control Panel.